Hi Fabiola.

I'll solve a similar problem to yours so you can see how it is solved.

When 9 times a number (x) is decreased by 100, the answer is the same as when 4 is increased by the first number (x). Find x.

So I write the equation by interpreting the words into mathematical symbols:

"9 times a number..." becomes "9x"

"...is decreased by 100..." becomes "- 100"

"...is the same as..." becomes "="

"...4 is increased by the first number" becomes "4 + x".

So 9x - 100 = 4 + x. Now I solve for x.

9x - 100 - x + 100 = 4 + x - x + 100

8x = 104

8x / 8 = 104 / 8

x = 13.

Now you do the same with your question.

Hope this helps,
Stephen La Rocque.