You make the denominators the same, by multiplying the fractions by the denominator of the other fraction. Then you can subtract them. For example, 4/5 - 7/8. Make the denominators the same by multiplying "4/5" by 8, which gives 32/40. Multiply "7/8" by 5, which gives 35/40. Denominators are now the same, so subtract: 32/40 - 35/40 = -3/40.Hope this helps! Good luck!
