So I have figured this out but I don't think this is the way I am suppose to write the equation fraction out.

8 1/2 years ago, Steven was 7 years old. How old is he now?

Do I write it out like this 8/1 + 1/2 + 7/1 ??? But it comes out too high of a number. I know I am doing it wrong. 8 1/2 + 7 = 15 1 /2 this is right. But can't be this easy. I am doing fractions adding and subtracting right now. Do I write it out f - 7 = 8 1/2 and f = 15 1/2 formula???

Is it f - 7 = 15 1/ 2 formula ?

This is correct.

8 1/2 + 7 = 15 1 /2

I know what is it! Is it f- 7 = 8 1/2

which equal 15 1/2

right ?? :)

Yes, that's right.

But don't I in one step 17/2 + 7/1 find LCD? which is 2 ??

Thank you.

If you must change these numbers to fractions, then >>

8 1/2 = 17/2

f - (14/2) = (17/2)

f = (17/2) + (14/2)

f = 31/2 = 15 1/2