Answer:
x = 4
Explanation:
Since both are equal to variable y, by deduction, the two equations are equal to each other. So we can set them equal to each other.
8x + 5 = 4x + 21
Now, we must get variables on one side and constants on the other. To do so, subtract 4x from both sides and 5 from both sides.
8x - 4x = 21 - 5
Combine like terms.
4x = 16
Now, divide both sides by 4 to isolate variable x.
4x / 4 = 16 / 4
x = 4