Question

Use suitable identity to find the product of (7 – 2y) (7 +2y).

Answer 1

Solution :

$\tt (7 - 2y) (7 +2y)$

By using identinty :

$\large \underline{\boxed{\bf{(a-b)(a+b) = a^2 - b^2}}}$

$\tt : \implies (7 - 2y) (7 +2y) = (7)^{2} - (2y)^{2}$

$\tt : \implies (7 - 2y) (7 +2y) = 49 - 4y^{2}$

$\large \underline{\boxed{\bf{(7 - 2y) (7 +2y) = 49 - 4y^{2}}}}$

Hence, value of (7 - 2y) (7 +2y) is 49 - 4y².