1,8(3) - 7/5 = ([80/100 × x + 0,2(7)] : 3
1,8(3) = (183-18)/90 = 165/90 = 11/6
1,8(3) - 7/5 = 11/6 - 7/5 = 55/30 - 42/30 = 13/30
Termenul din stanga semnului "egal" este deci 13/30
80/100 = 4/5
0,2(7) = (27-2)/90 = 25/90 = 5/18
Ecuația devine:
13/30 = (4/5 × x + 5/18) : 3
4/5 × x + 5/18 = 13/30 × 3
4/5 × x + 5/18 = 13/10
4/5 × x = 13/10 - 5/18
4/5 × x = 117/90 - 25/90
4/5 × x = 92/90
4/5 × x = 46/45
x = 46/45 : 4/5
x = 46/45 × 5/4
x = 23/18
R: x = 23/18 = 1,2(7)
