New Zealand
Level 7 - NCEA Level 2

# Defineable rational expressions

## Interactive practice questions

In the following expression, what values are not allowable as substitutions for the variable $x$x? Write your answer as an equation. If there is more than one value, make sure to enter all appropriate values separated by a comma.

$\frac{1}{x}$1x

Easy
Less than a minute

In the following expression, what values are not allowable as substitutions for the variable $x$x? Write your answer as an equation. If there is more than one value, make sure to enter all appropriate values separated by a comma.

$\frac{4}{15x}$415x

In the following expression, what values are not allowable as substitutions for the variable $z$z? Write your answer as an equation. If there is more than one value, make sure to enter all appropriate values separated by a comma.

$\frac{1}{z+7}$1z+7

In the following expression, what values are not allowable as substitutions for the variable $y$y? Write your answer as an equation. If there is more than one value, make sure to enter all appropriate values separated by a comma.

$\frac{y}{y-8}$yy8

### Outcomes

#### M7-6

Manipulate rational, exponential, and logarithmic algebraic expressions

#### 91261

Apply algebraic methods in solving problems