Odpowiedź :
a) x + (x + 8) = 40
x + x + 8 = 40
2x = 32
x = 16
b) x/2 - (x - 20) = 5
x/2 - x + 20 = 5
- x/2 = -15
x = 30
c) 6 × (x - 7) = 48
6x - 42 = 48
6x = 90
x = 15
d) 3x/4 = 9
3x = 36
x = 12
e) x + 3 = 3x
-2x = -3
x = 3/2
x = 1,5
f) x - 5 = 1/2 x
2x - 10 = x
x = 10