First, set the second equation with y as the isolated variable. To do this, subtract 4 from both sides to get
Now that you know the value of y, put that expression in for y in the first equation to get
Then, simplify by adding the x terms together to get
add 4 on both sides to isolate the x terms to get
then divide 6 from both sides to get
Using that x value, plug it into one of the equations as x to find y ( I will use y=3x-4)
x=1 and y=-1 is the answer