What is the answer to 4x plus 8 equals 2r plus 20?

Answer 1

That depends on what the question is. What you gave is simply a relationship between two variables. You can simplify it like this:

4x + 8 = 2r + 20

(4x + 8) / 2 = (2r + 20) / 2

2x + 4 = r + 10

2x + 4 - 4 = r + 10 - 4

2x = r + 6

You can then solve for x by dividing both sides by two:

2x / 2 = (r + 6) / 2

x = r/2 + 3

You could also solve for r by subtracting six from both sides, and rearranging the equation:

2x = r + 6

2x - 6 = r + 6 - 6

2x - 6 = r

r = 2x - 6

r = 2(x - 3)