X +4=3X -8 ????????????????

Răspuns :

x+4=3x-8
x+3x=4-8
4x=-4
x=4:(-4)
x=(-1)
S={-1}
x+4=3x-8
x-3x=-8-4
-2x=-12
x=-12:-2
x=6
6+4=3·6-8
10=10
deci, da ,e corect