Question 30432
no its answer is not zero and it is solved inthe follwing ways.

10/(x-7) - 10/(x+7) 

on taking the lCM of denominator we get...

[ 10(x+7) - 10(x-7) ] / (x+7)(x-7)

Now in the denomiator we apply the formula .. (a+b)(a-b) = (a)^2 - (b)^2..we get

[ 10(x+7) - 10(x-7) ] / (x)^2 - (7)^2

solving the denomiator  would give..

[ 10(x+7) - 10(x-7) ] / x^2 - 49

solving the numerator would give,,,

[ 10x + 70 - 10x + 70 ] / x^2 - 49

140 / x^2 - 49.