Solve one of the equations for one of the variables
Like:
-6x+3y=6
y=(6x+6)/3
y=2x+2
Then subistute it into the other one
5x-4(2x+2)=-14
Solve
5x-6x-4=-14
-x-4=-14
-x=-10
x=10
Then put 10 back into either original equation for x
-6(10)+3y=6
-60+3y=6
3y=66
y=22
x=10
y=22