Question

23. Factorize.
(1)
$343a {3} - 216b {3} - 882a {2}b + 756ab {2}$
(2)
$( - 2x + 5y - 3z) {2}$
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Answer 1

$1. \; \mathtt{343a³-216b³-882a²b+756ab²}$

$\mathtt{= (7a)³-(6b)³-3×(7a)²×6b+3×7a×(6b)²}$

$\mathtt{= (7a-6b)³}$

$\rm{Identity \; used \; :- \; (a-b)³ = a³-b³-3a²b+3ab²}$

$2. \; \mathtt{(-2x+5y-3z)²}$

$\mathtt{[(-2x)+5y+(-3z)]²}$

$\mathtt{= (-2x)²+(5y)²+(-3z)²+2×(-2x)×5y+2×5y×(-3z)+2×(-3z)×(-2x)}$

$\mathtt{4x²+25y²+9z²-20xy-30z+12zx}$

$\rm{Identity \; used \; :- \; (a+b+c)² = a²+b²+c²+2ab+2bc+2ca}$

$\rm{\bold{Swipe \; for \; answer \; →}}$

Answer 2

Step-by-step explanation:

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