Question

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$25a^2-16(b-2a{)}^2$

Answer 1

$25a^2-16(b-2a{)}^2$

$=(5a{)}^2-(4(b-2a){)}^2$ is of the form $a^2-b^2=(a-b)(a+b)$

$=(5a-4(b-2a\left)\right)(5a+4(b-2a\left)\right)$

$=(5a-4b+8a)(5a+4b-8a)$

$=(13a-4b)(4b-3a)$.