Twice the difference of a number and 9 is equal to three times the sum of the number and 7. Find the number.

Answer 1

Hello Karli,

let's call that number x.

"Twice the difference of a number and 9" means 2 * (x-9)

" is equal to" means =

"three times the sum of the number and 7" means 3* (x+7)

Put it all together: 2 * (x-9) = 3* (x+7)

-------> 2x - 18 = 3x + 21

From there it becomes a two-step equation. You could subtract 2x from both sides, then subtract 21 from both sides, and you will find the number.