Evaluate (1/(x+h)-1/x)/h

$\frac{\frac{1}{x + h} - \frac{1}{x}}{h}$

Step 1

Simplify the numerator.

To write $\frac{1}{x + h}$ as a fraction with a common denominator, multiply by $\frac{x}{x}$ .

$\frac{\frac{1}{x + h} \cdot \frac{x}{x} - \frac{1}{x}}{h}$

To write $- \frac{1}{x}$ as a fraction with a common denominator, multiply by $\frac{x + h}{x + h}$ .

$\frac{\frac{1}{x + h} \cdot \frac{x}{x} - \frac{1}{x} \cdot \frac{x + h}{x + h}}{h}$

Write each expression with a common denominator of $(x + h) x$ , by multiplying each by an appropriate factor of $1$ .

Multiply $\frac{1}{x + h}$ by $\frac{x}{x}$ .

$\frac{\frac{x}{(x + h) x} - \frac{1}{x} \cdot \frac{x + h}{x + h}}{h}$

Multiply $\frac{1}{x}$ by $\frac{x + h}{x + h}$ .

$\frac{\frac{x}{(x + h) x} - \frac{x + h}{x (x + h)}}{h}$

Reorder the factors of $(x + h) x$ .

$\frac{\frac{x}{x (x + h)} - \frac{x + h}{x (x + h)}}{h}$

Combine the numerators over the common denominator.

$\frac{\frac{x - (x + h)}{x (x + h)}}{h}$

Rewrite $\frac{x - (x + h)}{x (x + h)}$ in a factored form.

Apply the distributive property.

$\frac{\frac{x - x - h}{x (x + h)}}{h}$

Subtract $x$ from $x$ .

$\frac{\frac{0 - h}{x (x + h)}}{h}$

Subtract $h$ from $0$ .

$\frac{\frac{- h}{x (x + h)}}{h}$

Move the negative in front of the fraction.

$\frac{- \frac{h}{x (x + h)}}{h}$

Step 2

Multiply the numerator by the reciprocal of the denominator.

$- \frac{h}{x (x + h)} \cdot \frac{1}{h}$

Step 3

Cancel the common factor of $h$ .

Move the leading negative in $- \frac{h}{x (x + h)}$ into the numerator.

$\frac{- h}{x (x + h)} \cdot \frac{1}{h}$

Factor $h$ out of $- h$ .

$\frac{h \cdot - 1}{x (x + h)} \cdot \frac{1}{h}$

Cancel the common factor.

$\frac{h \cdot - 1}{x (x + h)} \cdot \frac{1}{h}$

Rewrite the expression.

$\frac{- 1}{x (x + h)}$

Step 4

Move the negative in front of the fraction.

$- \frac{1}{x (x + h)}$