C = (2x + 3)(5.x - 8) - (2x - 4)(5x - 1)
C= 10 x^2 -16x+15x -24 -(10x^2 -2x -20x+4)
C= 10x^2 -x-24- 10x^2+22x-4
C=21x-28
C=7× 3x - 7×4= 7 (3x-4)
Bonjour,
Développer puis réduire :
C = (2x+3)(5x-8)-(2x-4)(5x-1)
C = 10x²-16x+15x-24-(2x-4)(5x-1)
C = 10x²-16x+15x-24-(10x²-2x-20x+4)
C = 10x²-16x+15x-24-(10x²-22x+4)
C = 10x²-16x+15x-24-10x²+22x-4
C = -16x+15x-24+22x-4
C = 21x-24-8
C = 21x-28
Bonne journée.