devoir de mathématique aidé moi svp

bonsoir pour le 1)
(5x+3)+(3x-2) = 5x+3+3x-2 = 8x+1

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

2(3x-5)+4(2x+7) = 6x-10+8x+28 = 14x+18

3(4x-2)-2(x-5) = 12x-6-2x+10 = 10x+4

(x²+3x-5)+(3x²-6x+9) = x²+3x-5+3x²-6x+9 = 4x²-3x+4

x(2x+1)-(x²+5x-2) = 2x²+x-x²-5x+2 = x²-4x+2

(3x+5)(2x+7) = 6x²+21x+10x+35 = 6x²+31x+35

(2x-3)(3x-2) = 6x²-4x-9x+6 = 6x²-13x+6

x²+2+(3x-2)(3x-2) = x²+2+12x²-18x-8x+12 = 13x²-10x+14

8x-(x+1)(x-2) = 8x-(x²-2x+x-2) = 8x-x²+2x-x+2 = 9x-x²+2