Answer:
x = -41
y = 9
Explanation:
Begin by multiplying the top equation by 2
2x = -8y - 10
The second equation requires a little more care.
Start by moving 10y to the right. Normally the y value is on the left, but we are going to be substituting for 2x.
2x = - 10y + 8
What I've done is not the usual practice, but there is nothing wrong with it.
Now since both right sides are equal to 2x, you can substitute for them
-8y - 10 = -10y + 8 Add 10y to both sides
-8y + 10y - 10 = 8
2y - 10 = 8 Add 10 to both sides
2y = 8+10
2y = 18 Divide by 2
y = 18/2
y = 9
Use the second original equation to solve for x
2x + 10y = 8
2x + 10*9 = 8
2x + 90 = 8 Subtract 20 from both sides
2x = 8 - 90
2x = - 82 Divide by 2
x = -822/2
x = - 41