Răspuns :
0,4 = 4/10 = 2/5
0,5 = 5/10 = 1/2
a•2/5 = b•1/2 = k
a = 5k/2
b = 2k
5k/2 + 2k = 36
5k + 4k = 72
9k = 72
k = 8
a = 20
b = 16
0,5 = 5/10 = 1/2
a•2/5 = b•1/2 = k
a = 5k/2
b = 2k
5k/2 + 2k = 36
5k + 4k = 72
9k = 72
k = 8
a = 20
b = 16