Answer :
Add -5 times the second equation to 2 times the first to get:
10x-10y-15x+10y=20-10
Thus:
-5x=10
Divide by -5 to get:
x=-2.
Substitute this into the first equation to get:
-6-2y=2
Add 6 to get:
-2y=8
Divide by -2 to get y=-4.
10x-10y-15x+10y=20-10
Thus:
-5x=10
Divide by -5 to get:
x=-2.
Substitute this into the first equation to get:
-6-2y=2
Add 6 to get:
-2y=8
Divide by -2 to get y=-4.