Question

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1 (2x+3y+5)(2x+3y-5)​

Answer 1

$\red{ \boxed{(a + b)(a - b) = {a}^{2} - {b}^{2} }}$

$\implies {(2x + 3y )}^{2} - {5}^{2}$

$\implies {(2x + 3y )}^{2} - 25$

$\red{ \boxed{ {(a + b)}^{2} = {a}^{2} + 2ab + {b}^{2} }}$

$\implies {(2x)}^{2} + 2(2x)(3y) + {(3y)}^{2} - 25$

$\orange{ \therefore 4 {x}^{2} + 9 {y}^{2} + 12xy - 25}$