Răspuns :
a/4 = b/3
a + b = 140
a = 4b/3
4b/3 + b = 140
aducem la acelasi numitor
4b + 3b = 420
7b = 420
b = 420 : 7
b = 60
a = 140 - 60
a = 80
a + b = 140
a = 4b/3
4b/3 + b = 140
aducem la acelasi numitor
4b + 3b = 420
7b = 420
b = 420 : 7
b = 60
a = 140 - 60
a = 80