Réponse :
27)a.-7 b.43 c.12,5 d.4,25
28)a.-12 b.0,5 c.-34/21
a.9 b.-6 c.5
Explications étape par étape :
27)a.14=-2*x b.-86=-2*x c.-25=-2*x d.-17/2=-2*x
14/-2=x -86/-2=x -25/-2=x (-17/2)/-2=x
x=-7 x=43 x=12,5 -8,5/-2=x
x=4,25
28)a.-18/(2/3)=x b.(3/4)/(2/3)=x c.(-17/7)/(2/3)=x
x=-12 x=0,5 x=-34/21
a.6=2/3*x b.-4=2/3*x c.10/3=2/3*x
6(2/3)=x -4/(2/3)=x (10/3)/(2/3)=x
x=9 x=-6 x=5
