Step 1) Find common denominator. In this case it was 28.
Step 2) Multiply 1/4 by seven to get 7/28 and then 2/7 by 4 to get 14/28.
Step 3) Add numerators: 7+14 to get 21
Step 4) Simpify your new added Fraction 21/28= 3/4
Your answer is 3/4
Please let me know if you would like further explanation (:
