Răspuns :
a/3 = a - 100
100 = a - a/3
100 = 2a/3
2a = 100 x 3
2a = 300
a = 300 : 2
a =150
150 3 = 150 - 100
50 = 50
100 = a - a/3
100 = 2a/3
2a = 100 x 3
2a = 300
a = 300 : 2
a =150
150 3 = 150 - 100
50 = 50