Bonsoir
(3x+2)²-(2x-5)(5x-7)
= (3x)^2 + 2 * 3x * 2 + 2^2 - (2x - 5)(5x - 7)
= 9x^2 + 12x + 4 - (10x^2 - 14x - 25x + 35)
= 9x^2 + 12x + 4 - 10x^2 + 14x + 25x - 35
= -x^2 + 51x - 31
