Question

How do you evaluate `6+ \frac { z } { z + 5} - \frac { 5} { z ^ { 2} - 25}`?

Answer 1

`(7z^2-5z-155)/((z+5)(z-5))`

Explanation:

`6+z/(z+5)-5/(z^2-25)`

=`6+z/(z+5)-5/((z+5)(z-5))`

=`((6(z+5)(z-5))+z(z-5)-5)/((z+5)(z-5))`

=`(6z^2-150+z^2-5z-5)/((z+5)(z-5))`

=`(7z^2-5z-155)/((z+5)(z-5))`