Basic Math Examples

$\frac{4}{z^{2}} - \frac{7}{z}$

Step 1

To write $- \frac{7}{z}$ as a fraction with a common denominator, multiply by $\frac{z}{z}$ .

$\frac{4}{z^{2}} - \frac{7}{z} \cdot \frac{z}{z}$

Step 2

Write each expression with a common denominator of $z^{2}$ , by multiplying each by an appropriate factor of $1$ .

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Step 2.1

Multiply $\frac{7}{z}$ by $\frac{z}{z}$ .

$\frac{4}{z^{2}} - \frac{7 z}{z \cdot z}$

Step 2.2

Raise $z$ to the power of $1$ .

$\frac{4}{z^{2}} - \frac{7 z}{z^{1} z}$

Step 2.3

Raise $z$ to the power of $1$ .

$\frac{4}{z^{2}} - \frac{7 z}{z^{1} z^{1}}$

Step 2.4

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$\frac{4}{z^{2}} - \frac{7 z}{z^{1 + 1}}$

Step 2.5

Add $1$ and $1$ .

$\frac{4}{z^{2}} - \frac{7 z}{z^{2}}$

Step 3

Combine the numerators over the common denominator.

$\frac{4 - 7 z}{z^{2}}$