To add these fractions, we need to find a common denominator. The least common multiple of 7, 6, and 10 is 210.

Converting the fractions to have a denominator of 210:

(4/7) * (30/30) = 120/210
(5/6) * (35/35) = 175/210
(9/10) * (21/21) = 189/210

Now, we can add the fractions:

120/210 + 175/210 + 189/210 = (120 + 175 + 189)/210 = 484/210

The fraction 4/7 + 5/6 + 9/10 is equal to 484/210.