Question

se stie ca a:b=3,b:2=c a-b=40afla 3a-4b+5c

Answer 1

a:b=3
a-b=40
a=3b
3b-b=40
b=40?:2=20
a=20x3=60
20:2=c
c=10

3a-4b+5c=
3x60-4x20+5x10=
180-80+50=150

Answer 2

a:b=3
a=3b
b:2=c
a-b=40
3b-b=40
2b=40
b=20
20:2=c
c=10
a-20=40
a=60
3a-4b+5c=
3*60-4*20+5*10=
180-80+50=
100+50=150