
Amanda A. answered 05/16/13
Experienced Teacher and Education Professional w/ Test-Prep Experience
If I understand your question, it's asking what fraction you would add to the given fraction to equal 1. In fraction form, any time the denominator and numerator are equal, that equals one.
For example:
Setup your givens: 1 = 2/3 + x
Change the 1 into fraction form: 3/3 = 2/3 + x
Move the 2/3 over: 3/3 - 2/3 = x
Subtract: 1/3 = x
You can do that for each of the fractions in question. When you change the 1 into fraction form, you need to look at the denominator of your given fraction and use that for when you change your 1.