Question

Problema de fractii / cls. 5

a/b=7/5 si a*b = 1260
cine sunt a si b.

=> 5a = 7b si a = 1260/b
deci
5(1260/b) = 7b
5*1260 / 5b = 7b
6300 / 5b = 7b

unde am gresit pana aici ?

Answer 1

a/b=7/5      5a=7b    
a*b=1260  a=1260/b
5*1260/b=7b
6300/b=7b
7b²=6300
b²=900
b=30
a=1260/30=42