9x^2 - (7x-2) (x+3) = - 12x+1

9x^2 - (7x-2) (x+3) = - 12x + 1

9x^2 - [7x^2 + 21x - 2x - 6] = - 12x+1

9x^2 - 7x^2 - 19x + 6 + 12x - 1 = 0

2x^2 - 7x + 5 = 0

(x-1) (2x - 5) = 0

there are two answers

1. x = 1

2. x = 5/2 or 2 1/2

you can try and substitute these numbers in to see if they are correct, because they are for me

9x^ (2) - (7x-2) (x+3) = 12x+1

9x^ (2) - (7x^ (2)) - 2x+21x-6=-12x+1

2x^ (2) + 31x=7