A=6x+7+(4x-3)-(7x-5) = 6x +7 + 4x -3 -7x +5 = 3x +9
B=(4x²+6x-3)-(2x²+4x-7) = 4x² +6x -3 -2x² -4x +7 = 2x² +2x +4
C=3(2x+4)+5(4x=2) = 6x +12 +20x +10 = 26x +22
D=4(2x-3)-3(5-6x) = 8x -12x - (15 -18x) = 8x -12x -15 +18x = 14x -15
E=(2x+4)(4x+2) = 8x² + 4x +16x +8 = 8x² +20x +8
F=(-4x+-)(2x-3) = - 8x² +12x manque 1 chiffre
