Sagot :
Salut !
(x+2)(5+x) = 5x+x²+10+2x = x²+7x+10
(2x+3)(3x+1) = 6x²+2x+9x+3 = 6x²+11x+3
(5x-1)(2-3x) = 10x-15x²-2+3x = -15x²+13x-2
(-2-3x)(5x-3) = -10x+6-15x²+9x = -15x²-x+6
Salut !
(x+2)(5+x) = 5x+x²+10+2x = x²+7x+10
(2x+3)(3x+1) = 6x²+2x+9x+3 = 6x²+11x+3
(5x-1)(2-3x) = 10x-15x²-2+3x = -15x²+13x-2
(-2-3x)(5x-3) = -10x+6-15x²+9x = -15x²-x+6