Question

cum se rezolva ex:
3a-b=140
a-b=30
a=?;b=?

Answer 1

a=b+30
3(b+30)-b=140
3b+30-b=40
2b=40-30=10
b=10/5
b=2
a=30+2=32
Nu cred ca  e corect...

Answer 2

3a-b=140
a-b=30
a=30+b
3(30+b)-b=140
90+3b-b=140
90+2b=140
2b=140-90
2b=50
b=50:2
b=25
a=30+25
a=55
Verificare :  3x55-25=140