Question

factorise9(a+b)^2-12(a^2-B^2)+4(a-b)^2​

Answer 1

$9 {(a + b)}^{2} - 12( {a}^{2} - {b}^{2} ) + 4 {(a - b)}^{2} \\ = \\ 9 {(a + b)}^{2} - 6(a + b)(a - b) - 6(a - b)(a + b) + 4 {(a - b)}^{2} \\ = \\ 3(a + b)(3(a + b) - 2(a - b)) - 2(a - b)(3(a + b) - 2(a - b)) \\ = \\ (3(a + b) - 2(a - b))(3(a + b) - 2(a - b)) \\ \\ = {(3(a + b) - 2(a - b))}^{2}$