Question 975796
(1/49a^2) + (10/7a) +25

If the problem is 
[(1/7)a +5]^2, that is different.

((1/49)a^2 +(10/7) a +25

(1/7) a is not the same as (1/7a)

To expand a binomial, (a+b)^2
It is square the first, twice the product of each term, and square the second
a^2+2ab+b^2

(a-b)^2= a^2-2ab + b^2