Solve for x in first equation:
x-2y=7
Add “2y” to both sides
x=2y+7
Put this in to second equation:
3(2y+7)+2y=21
Solve for y:
Distribute the 3 into the ()
6y+21+2y=21
Combine the like y terms
8y+21=21
Subtract 21 from both sides
8y=0
Divide by 8 on both sides
y=0
Put this into the first solved equation:
x=2(0)+7
Solve for x:
Multiple 2(0)
x=0+7
Add 0 and 7
x=7
So the value of x is positive 7.
