A=(2+x)^2-3(x+7)
=(2×2)+(2×x)+(x×x)+(x×2)-(3×x)-(3×7)
=4+2x+x^2+2x-3x-21
=-17+x+x^2
B=(4-x)(-3-2x)+(x+1)^2
=-(4×3)-(4×2x)+(x×3)+(x×2x) +(x×x)+(x×1)+(1×1)+(x×1)
=-12-8x+3x+2x^2+x^2+x+1+x
=-11-3x+3x^2
C=(1-x)(2+x)-3x^2+x-7
=(1×2)+(1×x)-(x×2)-(x×x)-3x^2+x-7
=2+x-2x-x^2-3x^2+x-7
=-5-4x^2
D=(4-2x)^2-(4+2x)^2
=(4×4)-(4×2x)+(2x×2x)-(2x×4)-(4×4)-(4×2x)-(2x×2x)-(2x×4)
=16-8x+4x^2-8x-16-8x-4x^2-8x
=-32x
E=(x+1)^2-(x+1)
=(x×x)+(x×1)+(1×1)+(1×x)-x-1
=x^2+x+1+x-x-1
=x^2+x
F=7-x+2(x-2)(x-1)
=7-x+(2×x)(x-1))-(2×2)(x-1))
=7-x+2x(x-1)-4(x-1)
=7-x+(2x×x)-(2x×1)-(4×x)+(4×1)
=7-x+2x^2-2x-4x+4
=11+2x^2-7x
Distributivité
