Réponse :
A=(2x-7)(2-x)=4x-2x-14+7x= 9x -14
B= (4x-3)²=4x²+3²-2×4x×3=40x+9
C=(7x+4)(x+2)+(4x-1)(x+5)=7x²+14+4x+8+4x²+20x-x-5=11x²+23x+17
D=(2x+5)(-x+2)-3(x²+5x-7)=x+4x-5x+10-3x²-15x+21=-3x²-5x+31
E=4+(5x-7)(3x+3)=4+15x²+15x-21x-21=15x²-6x-21
J = (2-3)(4-5) (0-3)(0-5) (1-3)(2-5)
J = -1-1 -3-5 -2-3
J = -2 -8 -5
K = 4-8+5 0-0+5 1-4+5
K = 1 5 2
