so one way is to subsitute
from the first equation we know that x=3y+5
so we subsitte 3y+5 for x in the second equation
(3y+5)-4y=3
3y+5-4y=3
combine like terms
5-y=3
subtract 5 from both sdies
-y=-2
multiply -1
y=2
subsitute 2 for y
x=3(2)+5
x=6+5
x=11
x=11
y=2
(11,2)