Răspuns :
a + 3/7 × a = 700
a/1 + 3a/7 = 700
7a/7 + 3a/7 = 700
10a/7 = 700
a/7 = 700 : 10
a/7 = 70
a = 70 × 7
a = 490
a/1 + 3a/7 = 700
7a/7 + 3a/7 = 700
10a/7 = 700
a/7 = 700 : 10
a/7 = 70
a = 70 × 7
a = 490