Answer:
x = 3 and y = 0
Explanation:
3y+x=3
-2y+5x=15
Isolate y in 3y + x = 3 :

Substitute
in -2y + 5x = 15 :

Simplify the equation :

Isolate x in
:
Proving x = 3
Isolate y in
:
Proving y = 0
Your solved system of equations are x being 3, and y being 0.