Solve 5/z-7/-z

$$\frac { 5 } { z } - \frac { 7 } { - z }$$

Evaluate

$$\frac{12}{z}$$

Short Solution Steps

Factor -z.

$$\frac{5}{z}-\frac{7}{-z}$$

To add or subtract expressions, expand them to make their denominators the same. Least common multiple of z and -z is -z. Multiply \frac{5}{z} times \frac{-1}{-1}.

$$\frac{5\left(-1\right)}{-z}-\frac{7}{-z}$$

Since \frac{5\left(-1\right)}{-z} and \frac{7}{-z} have the same denominator, subtract them by subtracting their numerators.

$$\frac{5\left(-1\right)-7}{-z}$$

Do the multiplications in 5\left(-1\right)-7.

$$\frac{-5-7}{-z}$$

Do the calculations in -5-7.

$$\frac{-12}{-z}$$

Differentiate w.r.t. z

$$-\frac{12}{z^{2}}$$