Respuesta:
a)
-4+10 = 3x
6 = 3x
2 = x
b)
5x-10 = -40
5x = -40+10
5x = -30
x = -6
c)
3.(-5-2x) = -21
-15-6x = -21
-6x = -6
6 = 6x
1 = x
d)
-9x-3x = -24
-12x = - 24
24 = 12x
