5×+4=2×+10=

10×-20=10


Resposta :

(I)

5x + 4 = 2x + 10

5x - 2x = 10 - 4

3x = 6

x = 6/3

x = 2

(II)

10x - 20 = 10

10x = 10 + 20

10x = 30

x = 30/10

x = 3