Solving 2-step Equations

Introduction

In this lesson, you will learn how to solve 2-step equations using reverse operations. This is a great review for our previous posts on equations because we will be handling addition, subtraction, multiplication, and division in this lesson.

Solving 2-step Equations

5x + 13 = 48

The above equation is a 2-step equation. In order to solve this, we need to reverse the operation applied so that we can find the value of x. 

First let's look at the +13. 5x was added to 13 to get 48. We need to use the reverse of adding, which is subtracting, to find the value of x. So, 13-13 equals 0 and 48-13 equals 35.

Now we are left with

 5x = 35

Now, we have to divide because the reverse of multiplication is division:

5/5 equals 1 or 1x which is the same thing as x.

35/5 equals 7.

That means the value of x=7!

We can check this by solving the equation:

5 (7)+ 13 = 48

According to the Order of Operations, multiplication comes before addition:

35 + 13 = 48

So our answer, or solution, is correct!

5x + 13 = 48

x = 7

 Sheet 1 Solving 2-step Equations

Division in Equations

Introduction

In this lesson, you will learn how to divide equations. In our previous lessons, we learned how to add, subtract, and multiply equations. Well dividing equations is pretty much the same thing except you will be solving equations with division. So let's start!

Division in Equations 

Remember that when solving equations, you just want to get the value of x, or in other words, of the variable.

x / 4 = 80

In order to solve the above equation you need to use the reverse operation. The reverse, or opposite operation of division is multiplication. So, we will multiply 80 by 4 or 4 by 80 ( it doesn't matter) and we'll get the product of 320.

That means the variable x equals 320.

We can check this by replacing the x with 320 and solving the equation.

320 / 4 = 80

So the answer or solution is correct!

x / 4 = 80

x = 320

 Sheet 1 Dividing Equations

Addition in Equations

Introduction

In this lesson, you will learn how to perform addition in equations. Before we begin, let's review what an equation is in mathematics.

Equation

A statement that shows that two mathematical expressions are equal.

Addition in Equations

The main thing that you need to focus on when adding in equations is that you have to get the x alone. So, as an example, let's take a look at the following equation:

x + 12 = 56

In order to get the x alone, we need to do the reverse operation of addition, which is subtraction. We will turn the +12 into a -12 and then subtract 12 from both sides. So 12-12 equals 0 and 56-12 equals 44. So that means the x equals 44. We can check this by solving the equation like this:

44 + 12 = 56

So that means that 44 is the correct answer!

x + 12 = 56

x = 44

Sheet 1 Adding Equations