Fraction Help

Question

if  1 - 1 = 1 what is the value of x?

    _   _    _ 

    7   8    X

Answer 1

First find the least common denominator.  In this case, it would be 7*8 or 56.

 

1/7 = 8/56

1/8 = 7/56

 

So 1/7 - 1/8 = 8/56 - 7/56 = 1/56