Resposta:
a)
[tex]2x + 30 = 15 - 3[/tex]
[tex]2x + 30 = 12 \\ 2x = 12 - 30 \\ 2x = - 18 \\ x = - 9[/tex]
b)
[tex]5x - 20 = 45 - 15[/tex]
[tex]5x - 20 = 30 \\ 5x = 30 + 20 \\ 5x = 50 \\ x = 10[/tex]
c)
[tex]20 - 8 = 4x + 10[/tex]
[tex]12x = 4x + 10 \\ - 4x = 10 - 12 \\ - 4x = - 2 \\ x = \frac{1}{2} [/tex]
d)
e)
