Explications étape par étape:
F=3(2 x - 4) + 5 (3 - x)
=6x-12+15-5x
=6x-5x+15-12
F=x+3
G = 2 x ( 5 + 3 x ) - 4 ( x + 5)
=10x+6x²-4x-20
=6x²+10x-4x-20
G=6x²+6x-20
H= ( 4 x + 5) (3 x + 2)
=12x²+8x+15x+10
H=12x²+23x+10
I= (5 x - 2) ( x + 7)
=5x²+35x-2x-14
I=5x²+33x-14
J = ( x-5)(3 x + 5) + ( 4 x-2)(5 x - 2)
=(3x²+5x-15x-25)+(20x²-8x-10x+4)
=3x²+5x-15x-25+20x²-8x-10x+4
=20x²+3x²+5x-15x-8x-10x-25+4
=23x²+5x-33x-25+4
J =23x²-28x-21
