Test : A= 3x(2x+4)-x(2-3x) B= 3 (x sur deux + 7) +(6x-1)-x(15+7x)-3 C=(2x+5) (3x-4) +(-2x+3)(-5x-2) D=(2x+5)(3x-4)+(-2x+3)(-5x-2)

A= 3x(2x+4)-x(2-3x)
A = 6x²+12x-2x+6x²
A = 10x

B= 3 (x sur deux + 7) +(6x-1)-x(15+7x)-3
B = 3x/2+7+6x-1-15x-7x²-3
B = 3x/2-9x+4-7x²
B = -7x²+(3-18)x/2+4
B = -7x²-15x/2+4

C=(2x+5) (3x-4) +(-2x+3)(-5x-2)
C = 6x²-8x+15x-20+10x²+4x-15x-6
C = 16x²-4x-26

D=(2x+5)(3x-4)+(-2x+3)(-5x-2)
D = C