Question #d76c4

1 Answer
Nov 7, 2017

x=13 1/3 or 13.333...

Explanation:

In order to solve this, we set up a proportion. When we see 90%, we can automatically know that it also could be written as 90/100.

Since we want to know what 12 is 90% of, we can write a proportion that says "12 is 90% of x as 90 is 90% of 100." That proportion looks like the following:

12/x=90/100

Cross multiply.

90 * x = 90x
12 * 100 = 1200

Your equation now looks like 90x=1200. Balance this by dividing both sides by 90, and you will have your answer.

"90x"/90=1200/90
x=13 1/3 or 13.333...