Question

factorise 9 (a+b)^2 - 4 (3a-b)^2​

Answer 1

Step-by-step explanation:

$9( {a}^{2} + {b}^{2} + 2ab) - 4(3 {a}^{2} - {b}^{2} - 2ab) \\ \\ 9 {a}^{2} + 9 {b}^{2} + 18 ab - 36 {a }^{2} - 4 {b}^{2} + 8ab$