First, find the least common denominator. In this case it would be 8. If you are multiplying 4 by 2 to get 8, you must also multiply the numerator by 2.
1/8 + -3(2)/4(2)
1/8 + -6/8
Write all numerators above the common denominator.
1-6/8
Calculate.
-5/8
Hope this helps!
