Explicație pas cu pas:
a ) x + 3 = 17
x = 17 - 3
x = 14
b ) 2x - 3 = 13
2x = 13 + 3
2x = 16
x = 16 : 2
x = 8
c ) 2x - 4 = x + 7
2x - x = 4 + 7
x = 11
d ) 7x + 15 = 35
7x = 35 - 15
7x = 20
x = 20 / 7
e ) 13x + 45 = 38
13x = 38 - 45
13x = -7
x = - 7 / 13