x - y = 15
2x + 8 = 3y - 4
We can quickly get a temporary value for x by altering the original equation.
x - y = 15
Add y to both sides.
x = 15 + y
Now that we have a value of x, we can find the exact value of y.
2(15 + y) + 8 = 3y - 4
Distributive property.
30 + 2y + 8 = 3y - 4
Combine like terms.
38 + 2y = 3y - 4
Subtract 2y from both sides.
38 = y - 4
Add 4 to both sides.
y = 42
Now that we know the exact value of y, we can plug it back into the original equation.
x - 42 = 15
Add 42 to both sides.
x = 57
