Question

daca se stie ca a pe b este echivalentacu 2pe 3 si a+b=20,afla a si b

Answer 1

a/b=2/3⇒ (a+b)/b=(2+3)/3
20/b=5/3
b=20*3/5=12
a=20-12=8

Answer 2

a/b=2/3
a+b=20   a=20-b
(20-b)/b=2/3
2b=3(20-b)
2b=60-3b
2b+3b=60
5b=60
b=60/5    b=12
a+b=20
a=20-b=20-12=8     a=8