Calculer a la main
a=10,23-(5,91+2,23)
a=10,23-5.91-2.23
a=2.09
b=-7,41-(3,17-2,41)
b=-7.41-3.17+2.41
b=6.65
c=-(5,84+2,31)+6,84
c=10.37
d=-(13-6)-(-8-7)
d= 7+15
d=22
Developper et reduire
a=3x(-4x-7) a= -12x^2 - 21x
b=7(3x+1) b=21x+7
c=8-2(4x+1) c=8-8x+2 c=-8x +10
d=5x-3(x+1) d=5x-3x-3 d= 2x -3