Question

a) ×+42=84

b) 3x+20-12=-28

Answer 1

Respuesta:

$x = 84 - 42 \\ x = 42 \\ \\ 3x + 20 - 12 = - 28 \\ 3x = - 28 - 20 + 12 \\ 3x = 36 \\ x = \frac{36}{3} = 12 \\ x = 12$