# 9.1: X for Unknown

Look at the equation below. Can you figure out the value of ? In this concept, you will learn how to solve equations using the order of operations, distributive property, and square roots.

### Guidance

The **order of operations** tells us the correct order of evaluating math expressions. We always do ** parentheses first**. Then we do

**. Next we do**

*exponents***and finally**

*multiplication and division (from left to right)***. The**

*addition and subtraction (from left to right)***allows us to remove parentheses when there is an unknown inside of them.**

*distributive property*In order to evaluate expressions using the distributive property and the order of operations, we can use the problem solving steps to help.

- First,
**describe**what you see in the problem. What operations are there? - Second, identify what
**your job**is. In these problems, your job will be to solve for the unknown. - Third, make a
**plan**. In these problems, your plan should be to use the distributive property and the order of operations to get the by itself. At the end, you will use a square root. - Fourth,
**solve**. - Fifth,
**check**. Substitute your answer into the equation and make sure it works.

#### Example A

Solve for the positive value of . Show all steps.

**Solution:**

We can use problem solving steps to help us to solve this equation.

#### Example B

Solve for the positive value of . Show all steps.

**Solution:**

We can use problem solving steps to help us to solve this equation.

#### Example C

Solve for the positive value of . Show all steps.

**Solution:**

We can use problem solving steps to help us to solve this equation.

#### Concept Problem Revisited

We can use problem solving steps to help us to solve this equation.

### Vocabulary

The ** order of operations** tells us the correct order of evaluating math expressions. We always do

**. Then we do**

*parentheses first***. Next we do**

*exponents***and finally**

*multiplication and division (from left to right)***. The**

*addition and subtraction (from left to right)***allows us to remove parentheses when there is an unknown inside of them. The**

*distributive property***of a number is a value that, when multiplied by itself, gives the original number.**

*square root*### Guided Practice

Solve for the positive value of . Show all steps.

1.

2.

3.

**Answers:**

1. . Here are the steps to solve:

2. . Here are the steps to solve:

3. . Here are the steps to solve:

### Practice

Solve for the positive value of . Show all steps.

### Image Attributions

## Description

## Learning Objectives

Students apply the distributive property, use the order of operations, and take square roots to find the values of unknowns. Students willuse problem solving steps to help.