So first to find the length of board she had left we would have to find a common denominator for both fractions : 7/8 and 1/4. The greatest common factor of both fraction is 8 so we would adjust 1/4. Multiply both the numerator and denominator by 2 and you would get : 2/8. Now we can easily subtract the fractions by just subtracting the numerators : 7/8 - 2/8 = 5/8. So Jennifer has 5/8 of her board left. Hope this helped!
