Resposta :
a) 3x = 12
x = 12/3
x = 4
b) 73x - 53x = 100
20x = 100
x = 100/20 = 5
c) 5x + 10 - 13 = 6x - 6
5x - 6x = -6 -10 +13
-x = - 3
x = 3
a) 3x = 12
x = 12/3
x = 4
b) 73x - 53x = 100
20x = 100
x = 100/20 = 5
c) 5x + 10 - 13 = 6x - 6
5x - 6x = -6 -10 +13
-x = - 3
x = 3