Pay attention

$\large \frac { 1 }{ a } -\frac { 1 }{ a\quad \quad +\frac { 1 }{ 1-\quad \frac { 1 }{ a } } } \quad =\quad ?$

(If you need to evaluate the answer to the square use a²,b² etc..)

(x/x is a fraction. Example: 1/1 is the same as $\frac { 1 }{ 1 }$ )