Question

The equation r=10a-20 represents the revenue r (in dollars) you make by spending a dollar on advertising your revenue totaled $110. How much did you spend advertising?

Please help me

Answer 1

Your equation is 10a-20=$110 so first you + $20 both sides of the equal sign. So you cancelled out -20 by +20 and you added 20 to $110 so now your equation is 10a=$130 you divide by 10 on both sides and you're left with a=13. Hope this helped tried to make it as clear as possible.