Question

a+b=90
a de 8 ori mai mic decat b
a=?,b=?

Answer 1

a+b=90
8a=b

a+8a=90
9a=90
a=90:9
a=10

b=8*10
b=80

Answer 2

A+B=90

A=B:8 

A+B=90

B:8+B=90/x8

b+8b=720    a=b:8

9b=720/:9     a=80:8  

b=80              a=10