Question

factorise 3 x square - 20 x-7

Answer 1

Here we go,
$3 {x}^{2} - 20x - 7 \\ = 3 {x}^{2} - 21x + x - 7 \\ = 3x(x - 7) + (x + 7) \\ = (3x + 1)(x - 7)$


And we are done.

Answer 2

Hey mate ☺
I hope it helps you
Thanks