Question

how to factorise
$9 {x}^{2} - 30x + 25 - 4 {y}^{2}$

Answer 1

9{x}^{2}-4{y}^{2}-30x+25

= {3x}^{2}-{2y}^{2}-5(6x+5)

=(3x+2y)(3x-2y)-5(6x+5)

Hope it helps! :)