Réponse:
Exo 1:
A=5(-2x+4)
A= 5×(-2x) +5×4
A= -10x+20
B= -3(6-4x)
B= -3×6-3×(-4x)
B= -18+12x
B= 12x-18
C= -40(-5+3x)
C= -40×(-5) -40×3x
C= 200-120x
C=-120x+200
D=2(x+5) +3(x-2)
D= 2×x+2×5+3×x+3×(-2)
D= 2x+10+3x-6
D= 5x+4
E=-4(2x+7) +4(-3x+2)
E= -4×2x-4×7+4×(-3x) -4×2
E= -8x-28-12x-8
E= -20x-36
Exo 2:
15×3x=45x
-7x-2×2= impossible
6x×(-30) = -180x
4x×2x= 8x²
-3x+9x= 6x
15+5x= impossible
80+5x= impossible
4-8x= impossible
7x+2×2+6x-4= 13x