Add the Rational Expressions $\frac { a - 7 } { a } - \frac { 1 } { a + 7 }$

Short Answer

Add the rational expressions. Be sure to express your answer in simplest form. $\frac { a - 7 } { a } - \frac { 1 } { a + 7 }$ Please enter your answer as one fraction with the denominator factored completely and the numerator not factored.