Find the Domain and Range (7x)/(9x-1)

$\frac{7 x}{9 x - 1}$

Step 1

Set the denominator in $\frac{7 x}{9 x - 1}$ equal to $0$ to find where the expression is undefined.

$9 x - 1 = 0$

Step 2

Solve for $x$ .

Add $1$ to both sides of the equation.

$9 x = 1$

Divide each term in $9 x = 1$ by $9$ and simplify.

Divide each term in $9 x = 1$ by $9$ .

$\frac{9 x}{9} = \frac{1}{9}$

Simplify the left side.

Cancel the common factor of $9$ .

Cancel the common factor.

$\frac{9 x}{9} = \frac{1}{9}$

Divide $x$ by $1$ .

$x = \frac{1}{9}$

Step 3

The domain is all values of $x$ that make the expression defined.

Interval Notation:

$(- \infty, \frac{1}{9}) \cup (\frac{1}{9}, \infty)$

Set-Builder Notation:

${x | x \neq \frac{1}{9}}$

Step 4

The range is the set of all valid $y$ values. Use the graph to find the range.

Interval Notation:

$(- \infty, \frac{7}{9}) \cup (\frac{7}{9}, \infty)$

Set-Builder Notation:

${y | y \neq \frac{7}{9}}$

Step 5

Determine the domain and range.

Domain: $(- \infty, \frac{1}{9}) \cup (\frac{1}{9}, \infty), {x | x \neq \frac{1}{9}}$

Range: $(- \infty, \frac{7}{9}) \cup (\frac{7}{9}, \infty), {y | y \neq \frac{7}{9}}$

Step 6