Question

daca x/y este 3/5 iar suma lor rste 40 atunci 3x+y este egal cu.............

Answer 1

$\frac{x}{y} = \frac{3}{5}$⇒$\frac{x}{3}= \frac{y}{5}=k$⇒x=3k,y=5k
x+y=40
3k+5k=40
8k=40
k=5⇒x=15,y=25
3x+y=3*15+25=45+25=70