સ્વાધ્યાય: અવયવીકરણ
Solutions for GSEB Class 8 ganit Chapter avayavikaran Exercises.
Q-1. સ્વાધ્યાય 12.1
1. આપેલાં પદોમાં સામાન્ય અવયવ મેળવો.
(i) $$12x, 36$$
$$12x$$ ના અવયવ $$= 2\times 2\times 3\times x$$
$$36$$ ના અવયવ $$= 2\times 2\times 3\times 3$$
$$12x$$ અને $$36$$ ના સામાન્ય અવયવ $$= 2\times 2 \times 3 = 12$$
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(ii) $$2y, 22xy$$
$$2y$$ ના અવયવ $$= 2\times y$$
$$22xy$$ ના અવયવ $$= 2\times 11\times x\times y$$
$$12x$$ અને $$36$$ ના સામાન્ય અવયવ $$= 2\times y = 2y$$
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(iii) $$14pq, 28p^2q^2$$
$$14pq$$ ના અવયવ $$= 2\times 7\times p\times q$$
$$28p^2q^2$$ ના અવયવ $$= 2\times 2\times 7\times p\times p\times q\times q$$
$$12x$$ અને $$36$$ ના સામાન્ય અવયવ $$= 2\times 7\times p\times q = 14pq$$
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(iv) $$2x, 3x^2, 4$$
$$2x$$ ના અવયવ $$= 2\times x$$
$$3x^2$$ ના અવયવ $$= 2\times x\times x$$
$$4 $$ના અવયવ $$= 2\times 2$$
$$2x, 3x^2$$ અને $$4$$ ના સામાન્ય અવયવ $$= 1$$
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(v) $$6abc, 24ab^2, 12a^2b$$
$$6abc$$ ના અવયવ $$= 2\times 3\times a\times b\times c$$
$$24ab^2$$ ના અવયવ $$= 2\times 2\times 2\times 3\times a\times b\times b$$
$$12a^2b$$ ના અવયવ $$= 2\times 2\times 3\times a\times a\times b$$
$$6abc, 24ab^2$$ અને $$12a^2b$$ ના સામાન્ય અવયવ $$= 2\times 3\times a\times b = 6ab$$
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(vi) $$16x^3, -4x^2, 32x$$
$$16x^3$$ ના અવયવ $$= 2\times 2\times 2\times 2\times x\times x\times x$$
$$-4x^2$$ ના અવયવ $$= -1\times 2\times 2\times x\times x$$
$$32x$$ ના અવયવ $$= 2\times 2 \times 2\times 2\times 2\times x$$
$$16x^3, -4x^2$$ અને $$32x$$ ના સામાન્ય અવયવ $$= 2\times 2\times x = 4x$$
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(vii) $$10pq, 20gr, 30rp$$
$$10pq$$ ના અવયવ $$= 2\times 5\times p\times q$$
$$20gr$$ ના અવયવ $$= 2\times 2\times 5\times q\times r$$
$$30rp$$ ના અવયવ $$= 2\times 3\times 5\times r\times p$$
$$10pq, 20gr$$ અને $$30rp$$ ના સામાન્ય અવયવ $$= 2\times 5 = 10$$
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(viii) $$3x2y^3, 10x^3y^2, 6x^2y^2z$$
$$3x2y^3$$ ના અવયવ $$= 3\times x\times x\times y\times y\times y$$
$$10x^3y^2$$ ના અવયવ $$= 2\times 5\times x\times x\times x\times y\times y$$
$$6x^2y^2z$$ ના અવયવ $$= 3\times 2\times x\times x\times y\times y\times z$$
$$16x^3, -4x^2$$ અને $$32x$$ ના સામાન્ય અવયવ $$= x^2\times y^2 = x^2y^2$$
2. આપેલી પદાવલિઓના અવયવ મેળવો.
(i) $$7x - 42$$
$$= (7\times x)-(2\times 3\times 7)$$
$$=7(x-6)$$
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(ii) $$6p - 12q$$
$$= (2\times 3\times p)-(2\times 2\times 3\times q)$$
$$= 2\times 3[p-(2\times q)]$$
$$= 6(p-2q)$$
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(iii) $$7a^2 + 14a$$
$$= (7 \times a\times a) + (2\times 7\times a)$$
$$= 7 \times a [a + 2] $$
$$= 7a (a + 2)$$
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(iv) $$-16z + 20z^3$$
$$= -(2\times 2\times 2\times 2\times z) + (2\times 2\times 5\times z\times z\times z)$$
$$= 2\times 2\times z[-(22\times 2\times z2)+(5\times z\times z)]$$
$$= 4z(-4+5z^2)$$
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(v) $$20l^2m + 30alm$$
$$= (2\times 2\times 5\times l\times l\times m) + (2\times 3\times 5\times a\times l\times m)$$
$$= (2 \times 5 \times l\times m) [(2\times l) + (3 \times a)]$$
$$= 10 lm(2l + 3a)$$
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(vi) $$5x^2y-15xy^2$$
$$=(5\times x\times x\times y)-(3\times 5\times x\times y\times y)$$
$$=5\times x\times y[x-(3\times y)]$$
$$= 5xy(x-3y)$$
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(vii) $$10a^2 - 15b^2 + 20c^2 $$
$$ = 2\times 5\times a\times a-1\times 3\times 5\times b\times b + 2\times 2\times 5\times c\times c$$
$$ = 5 \times (2\times a\times a-1\times 3\times b\times b + 2\times 2\times c\times c)$$
$$ = 5(2a^2-3b^2+4c^2 )$$
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(viii) $$-4a^2 + 4ab - 4ca $$
$$ = -1\times 2\times 2\times a\times a + 2\times 2\times a\times b -1\times 2\times 2\times c\times a $$
$$ = 2 \times 2 \times a(-a+b-c)$$
$$ = 4a(-a+b-c)$$
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(ix) $$x^2yz + xy^2z + xyz^2$$
$$ = x\times x\times y\times z + x\times y\times y\times z + x\times y\times z\times z$$
$$= x\times y\times z(x+y+z)$$
$$= x\times y\times z(x+y+z)$$
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(x) $$ax^2y + bxy^2 + cxyz$$
$$ = a\times x\times x\times y + b\times x\times y\times y + c\times x\times y\times z$$
$$ = x\times y\times (a\times x+b\times y+c\times z)$$
$$ = xy(ax+by+cz)$$
3. અવયવ મેળવો.
(i) $$x^2 + xy + 8x + 8y$$
$$ = x \times x + x \times y + 8 \times x + 8 \times y$$
$$ = x(x + y) + 8(x + y)$$
$$ = (x + 8)(x + y)$$
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(ii) $$15xy-6x+5y-2 $$
$$ = 3 \times 5 \times x \times y - 2 \times 3 \times x + 5 \times y - 2 $$
$$ = 3x(5y-2)+1 (5y-2)$$
$$ = (5y-2) (3x+1)$$
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(iii) $$ax + bx - ay- by$$
$$= a \times x + b \times x-a \times y-b \times y$$
$$= x(a+b) - y(a+b)$$
$$= (a + b) (x - y)$$
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(iv) $$15pq+15+9q+ 25p$$
$$= 15pq + 9q + 25p + 15$$
$$= 3\times 5\times \times p\times q + 3\times 3 \times q + 5\times 5\times p + 3\times 5$$
$$= 3q (5p+3)+5 (5p+3)$$
$$= (5p+3) (3q+5)$$
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(v) $$z- 7 + 7xy – xyz$$
$$= z - x\times y\times z - 7 + 7\times x\times y$$
$$= (1-xy) - 7(1-xy)$$
$$= (1 - xy )(z - 7)$$
Q-2. સ્વાધ્યાય 12.2
1. નીચેની પદાવલિઓના અવયવ મેળવો.
(i) $$a^2 + 8a+ 16$$
$$= a^2+2\times 4\times a+4^2$$
$$= (a+4)2$$
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(ii) $$p^2 - 10p+ 25$$
$$= p^2-2\times 5\times p+5^2$$
$$= (p-5)^2$$
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(iii) $$25m^2 + 30m +9$$
$$= (5m)^2+2\times 5m\times 3+3^2$$
$$= (5m+3)^2$$
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(iv) $$49y^2+84yz+36z^2$$
$$=(7y)^2+2\times 7y\times 6z+(6z)^2$$
$$= (7y+6z)^2$$
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(v) $$4x^2 + 8x+4$$
$$= (2x)^2-2\times 4x+2^2$$
$$= (2x-2)^2$$
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(vi) $$121b^2 - 88bc + 16c^2$$
$$= (11b)^2-2\times 11b\times 4c+(4c)^2$$
$$= (11b-4c)^2$$
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(vii) $$(l + m)^2 - 4lm$$ (સૂચન : $$(l + m)^2$$ નું વિસ્તરણ કરો.)
$$= l^2+m^2+2lm-4lm$$
$$= l^2+m^2-2lm$$
$$= (l-m)^2$$
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(viii) $$a^4 + 2a^2b^2 + b^4$$
$$= (a^2)^2+2\times a^2\times b^2+(b^2)^2$$
$$= (a^2+b^2)^2$$
2. અવયવ મેળવો.
(i) $$4p^2 - 9q^2$$
$$= (2p)^2-(3q)^2$$
$$= (2p-3q)(2p+3q)$$
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(ii) $$63a^2 - 112b^2$$
$$= 7(9a^2 –16b^2)$$
$$= 7((3a)^2–(4b)^2)$$
$$= 7(3a+4b)(3a-4b)$$
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(iii) $$49x^2 - 36$$
$$= (7x)^2 -6^2$$
$$= (7x+6)(7x–6)$$
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(iv) $$16x^5 - 144x^3$$
$$= 16x^3(x^2–9)$$
$$= 16x^3(x^2–9)$$
$$= 16x^3(x–3)(x+3)$$
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(v) $$(l + m)^2 - (l − m)^2$$
$$= (l+m–l+m)(l+m+l–m)$$
$$= (2m)(2l)$$
$$= 4 ml$$
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(vi) $$9x^2y^2 - 16$$
$$= (3xy)^2-4^2$$
$$= (3xy–4)(3xy+4)$$
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(vii) $$(x^2 - 2xy + y^2) — z^2$$
$$= (x–y)^2–z^2$$
$$= {(x–y)–z}{(x–y)+z}$$
$$= (x–y–z)(x–y+z)$$
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(viii) $$25a^2 - 4b^2 + 28bc - 49c^2 $$
$$= 25a^2–(4b2-28bc+49c2 )$$
$$= (5a)^2-{(2b)^2-2(2b)(7c)+(7c)^2}$$
$$= (5a)^2-(2b-7c)2$$
$$= (5a+2b-7c)(5a-2b+7c)$$
3. પદાવલિના અવયવ મેળવો.
(i) $$ax^2 + bx$$
$$= x(ax+b)$$
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(ii) $$7p^2 + 21q^2$$
$$ = 7(p^2+3q^2)$$
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(iii) $$2x^3 + 2xy^2 + 2xz^2$$
$$ = 2x(x^2+y^2+z^2)$$
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(iv) $$am^2 + bm^2 + bn^2 + an^2$$
$$= m^2(a+b)+n^2(a+b) $$
$$= (a+b)(m^2+n^2)$$
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(v) $$(lm + l) + m + 1$$
$$= lm+m+l+1 $$
$$= m(l+1)+(l+1) $$
$$= (m+1)(l+1)$$
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(vi) $$y(y + z) + 9(y + z)$$
$$= (y+9)(y+z)$$
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(vii) $$5y^2 - 20y - 8z + 2yz $$
$$= 5y(y–4)+2z(y–4) $$
$$= (y–4)(5y+2z)$$
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(viii) $$10ab + 4a + 5b + 2$$
$$= 5b(2a+1)+2(2a+1) $$
$$= (2a+1)(5b+2)$$
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(ix) $$6xy - 4y + 6 - 9x$$
$$= 6xy–9x–4y+6 $$
$$= 3x(2y–3)–2(2y–3)$$
$$= (2y–3)(3x–2)$$
4. અવયવ મેળવો.
(i) $$a^4 - b^4$$
$$= (a^2)^2-(b^2)^2$$
$$= (a^2-b^2) (a^2+b^2)$$
$$= (a – b)(a + b)(a^2+b^2)$$
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(ii) $$p^4 - 81$$
$$= (p^2)^2-(9)^2$$
$$= (p^2-9)(p^2+9)$$
$$= (p^2-3^2)(p^2+9)$$
$$=(p-3)(p+3)(p^2+9)$$
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(iii) $$x^4 - (y + z)^4$$
$$= {x^2-(y+z)2}{ x^2+(y+z)^2}$$
$$= {(x –(y+z)(x+(y+z)}{x^2+(y+z)^2}$$
$$= (x–y–z)(x+y+z) {x^2+(y+z)^2}$$
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(iv) $$x^4 − (x – z)^4$$
$$= {x^2-(x-z)^2}{x^2+(x-z)^2}$$
$$= { x-(x-z)}{x+(x-z)} {x^2+(x-z)^2}$$
$$= z(2x-z)( x^2+x^2-2xz+z^2)$$
$$= z(2x-z)( 2x^2-2xz+z^2)$$
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(v) $$a^4 - 2a^2b^2 + b^4$$
$$= (a^2-b^2)^2$$
$$= ((a–b)(a+b))^2$$
$$= (a – b)^2 (a + b)^2$$
5. નીચેની પદાવલિના અવયવ મેળવો.
(i) $$p^2 + 6p + 8$$
$$= p^2+2p+4p+8 $$
$$= p(p+2)+4(p+2)$$
$$= (p+2)(p+4)$$
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(ii) $$q^2 - 10q + 21$$
$$= q^2–3q-7q+21$$
$$= q(q–3)–7(q–3)$$
$$= (q–7)(q–3)$$
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(iii) $$p^2 + 6p - 16$$
$$= p^2–2p+8p–16$$
$$= p(p–2)+8(p–2)$$
$$= (p+8)(p–2)$$
Q-3. સ્વાધ્યાય 12.3
1. ભાગફળ શોધો.
(i) $$28x^4 \div 56x$$
$$ = \frac{2 \times 2 \times 7 \times x \times x \times x \times x }{2 \times 2 \times 2 \times 7 \times x}$$
$$ = \frac{x^3}{2}$$
$$ = \frac{1}{2}x^3$$
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(ii) $$-36y^3 \div 9y^2$$
$$ = \frac{ - 2 \times 2 \times 3 \times 3 \times y \times y \times y }{3 \times 3 \times y \times y }$$
$$ = -4y$$
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(iii) $$66pq^2r^3 \div 11qr^2$$
$$ = \frac{2 \times 3 \times 11\times p\times q \times q \times r\times r\times r }{11 \times q \times r \times r }$$
$$ = 6pqr$$
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(iv) $$34x^3y^3z^3 \div 51xy^2z^3$$
$$ = \frac{2 \times 17 \times x \times x \times x \times y \times y \times y \times z \times z\times z}{3 \times 17 \times x \times y \times z\times z \times z}$$
$$ = \frac{2}{3}x^2y$$
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(v) $$12a^8b^8 \div (-6a^6b^4)$$
$$ = \frac{ 2 \times 2 \times 3 \times a^6 \times a^2\times b^4 \times b^4}{-2 \times 3 \times a^6 \times b^4}$$
$$ = -2a^2b^4$$
2. આપેલ બહુપદીને એકપદી વડે ભાગો.
(i) $$(5x^2-6x) \div 3x$$
$$ = \frac{x(5x - 6)}{3x}$$
$$ = \frac{1}{3}(5x - 6)$$
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(ii) $$(3y^8–4y^6+5y^4) \div y^4$$
$$ = \frac{y^4(3y^4 - 4y^2 + 5)}{y^4}$$
$$ = 3y^4 - 4y^2 + 5$$
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(iii) $$8(x^3y^2z^2+x^2y^3z^2+x^2y^2z^3) \div 4x^2 y^2 z^2$$
$$ = \frac{8x^2 y^2 z^2(x + y + z)}{4x^2 y^2 z^2}$$
$$ = 2(x + y + z)$$
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(iv) $$(x^3+2x^2+3x) \div 2x$$
$$ = \frac{x(x^2+2x+3)}{2x}$$
$$ = \frac{1}{2}(x^2+2x+3)$$
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(v) $$(p^3q^6–p^6q^3) \div p^3q^3$$
$$ = \frac{p^3q^3(p^3 - q^3)}{p^3q^3}$$
$$ = p^3 - q^3$$
3. નીચેના ભાગાકાર કરો.
(i) $$(10x–25) \div 5$$
$$ = \frac{5(2x - 5)}{5}$$
$$ = 2x - 5$$
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(ii) $$(10x–25) \div (2x–5)$$
$$ = \frac{5(2x–5)}{(2x–5)}$$
$$ = 5$$
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(iii) $$10y(6y+21) \div 5(2y+7)$$
$$ = \frac{10y\times 3 (2y+7)}{5(2y+7)}$$
$$ = 6y$$
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(iv) $$9x^2y^2(3z–24) \div 27xy(z–8)$$
$$ = \frac{9x^2y^2\times 3(z–8)}{27xy(z–8)}$$
$$ = xy$$
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(v) $$96abc(3a - 12)(5b - 30) \div 144(a - 4) (b - 6) $$
$$ = \frac{96abc\times 3(a - 4) \times 5(b - 6)}{144(a - 4) (b - 6)}$$
$$ = 10abc$$
4. સૂચવ્યા મુજબ ભાગાકાર કરો.
(i) $$5(2x+1)(3x+5) \div (2x+1)$$
$$ = \frac{5(2x+1)(3x+5)}{(2x+1)}$$
$$ = 5(3x+5)$$
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(ii) $$26xy(x+5)(y–4)\div 13x(y–4)$$
$$ = \frac{26xy(x+5)(y–4)}{13x(y–4)}$$
$$ = 2y(x+5)$$
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(iii) $$52pqr(p+q)(q+r)(r+p) \div 104pq(q+r)(r+p)$$
$$ = \frac{52pqr(p+q)(q+r)(r+p)}{104pq(q+r)(r+p)}$$
$$ = \frac{1}{2}r(p+q)$$
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(iv) $$20(y+4) (y^2+5y+3) \div 5(y+4)$$
$$ = \frac{20(y+4) (y^2+5y+3) }{5(y+4)}$$
$$ = 4(y^2+5y+3)$$
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(v) $$x(x+1)(x+2)(x+3) \div x(x+1)$$
$$ = \frac{x(x+1)(x+2)(x+3)}{x(x+1)}$$
$$ = (x+2)(x+3)$$
5. આપેલી પદાવલિના અવયવ મેળવો અને સૂચવ્યા મુજબ ભાગાકાર કરો.
(i) $$(y^2+7y+10)\div (y+5)$$
$$ = \frac{(y^2+7y+10)}{(y+5)}$$
$$ = \frac{(y+2)(y+5)}{(y+5)}$$
$$ = y + 2$$
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(ii) $$(m^2–14m–32)\div (m+2)$$
$$ = \frac{(m^2–14m–32)}{(m+2)}$$
$$ = \frac{(m–16)(m+2)}{(m+2)}$$
$$ = m - 16$$
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(iii) $$(5p^2–25p+20)\div (p–1)$$
$$ = \frac{(5p^2–25p+20)}{(p–1)}$$
$$ = \frac{5(p–1)(p–4)}{(p–1)}$$
$$ = 5(p-4)$$
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(iv) $$4yz(z^2+6z–16)\div 2y(z+8)$$
$$ = \frac{4yz(z^2+6z–16)}{2y(z+8)}$$
$$ = \frac{4yz(z–2)(z+8)}{2y(z+8)}$$
$$ = 2z(z-2)$$
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(v) $$5pq(p^2–q^2)\div 2p(p+q)$$
$$ = \frac{5pq(p^2–q^2)}{2p(p+q)}$$
$$ = \frac{5pq(p–q)(p+q)}{2p(p+q)}$$
$$ = \frac{5}{2}q(p–q)$$
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(vi) $$12xy(9x^2–16y^2)\div 4xy(3x+4y)$$
$$ = \frac{12xy(9x^2–16y^2)}{4xy(3x+4y)}$$
$$ = \frac{12xy(3x+4y)(3x-4y)}{4xy(3x+4y)}$$
$$ = 3(3x-4y)$$
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(vii) $$39y^3(50y^2–98) \div 26y^2(5y+7)$$
$$ = \frac{39y^3(50y^2–98)}{26y^2(5y+7)}$$
$$ = \frac{39y^3 \times 2(5y–7)(5y+7)}{26y^2(5y+7)}$$
$$ = 3y(5y - 7)$$