( 7 + x ) * 4 + x = 108
=> 28 + 4x + x = 108
=> 28 + 5x = 108
=> 5x = 80
=> x = 16 (tm)
(7 + x ) * 4 + x = 108
7 * 4 + x * 4 + x = 108
28 + x * 5 = 108
x * 5 = 108 - 28
x * 5 = 80
x = 80 : 5
x = 16
( 7 + x ) x 4 + x = 108
7 x 4 + x x 4 + x = 108
28 + x x 5 = 108
x x 5 = 108 - 28
x x 5 = 80
x = 80 : 5
x = 16