Resposta:
a) 3x + 5 = 8
3x = 8 - 5
3x = 3
x = 3/3
x = 1
b) 10x - 19 = 21
10x = 21 + 19
10x = 40
x = 40/10
x = 4
c) 2x - 7 = - 10
2x = - 10 + 7
2x = - 3
[tex]x = - \frac{3}{2} [/tex]
d) 5x - 27 = - 4x
5x + 4x = 27
9x = 27
x = 27/9
x = 3
e) 9x + 5 = 4x
9x - 4x = - 5
5x = - 5
x = -5/5
x = - 1
