Solving Two-Step Equations

Solving Two-Step Equations

Learning Objective

I can solve two-step equations in one variable.

How can you solve a two step equation?

A two step equation, like the one shown below, involves two operations.

 $2x+3=15$  

To solve a two step equation, work backward to undo operations. Reverse the order of operations. For example, to solve 2x+3=15, you can use subtraction first to undo the addition, and then use division to undo the multiplication.

How to get rid of a fraction?

Solving with two terms in the numerator, look at the example below.

 $\frac{x-7}{3}=12$  

What operation should you perform first?
Multiplication. When you multiply by the denominator of the frqaction in the equation, you get a on-step equation. So, multiplying first gets rid of the fraction.

Word problem.

The junior class is selling granola bars to raise money. They purchased 1250 granola bars and paid a delivery fee of $25. The total cost, including the delivery fee, was $800. What was teh cost of each granola bar?

Multiple Choice

50 = 28.1 + 0.15a

• a= 150

• a= 146

• a= 6

• a= 155

Multiple Choice

 $7+\frac{a}{3}=5$  

• a= -2

• a= -6

• a= 3

• a= 15

Multiple Choice

33 = 4a - 7

• a=-10

• a=10

• a=4.5

Multiple Choice

What is the first step in solving the following equation?

3x - 5 = 20

• multiply both sides by 5

• add 5 to both sides

• divide both sides by 5

• subtract both sides by 5

Multiple Choice

The goal of solving two-step equations is to:

• francine

• Find the coefficient

• Find the value of the variable