Solving 2-step Equations

Solving 2-step Equations

Essential Understanding

• you are solving by forming equivalent equations.

• a 2-step equation involves two operations to undo

• you will undo the operations in reverse order

Solving a Two-Step

 $2x+3=15$  

Solving With Two Terms In the Numerator

When on side of an equation is a fraction with more than one term in the numerator, you can still undo division by multiplying each side by the denominator.

Using an equation as a model

• What do you know?

• What do you need?

• What's my plan?

• Write and solve an equation.

Multiple Choice

Which equation would represent this problem the best.

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 the cost of each granola bar?

• 1250g + 25 = 800

• 1250g = 800 - 25

• 800g + 25 = 12500

What properties are use to solve?

• There are hidden steps that we assume are true.

• For solving equations we focus on properties of equality

Multiple Choice

What property of equality would you use to solve this equation in the first step.

 $-8=\frac{s}{4}+3$  

• Addition prop. of equality

• Subtraction prop. of equality

• Multiplicaion prop. of equality

• Dividion prop. of equality 

Multiple Choice

What property of equality would you use to solve this equation in the first step.

 $2x-9=7$  

• Addition prop. of equality

• Subtraction prop. of equality

• Multiplicaion prop. of equality

• Dividion prop. of equality 

Multiple Choice

What property of equality would you use to solve this equation in the first step.

 $\frac{x-8}{3}=4$  

• Addition prop. of equality

• Subtraction prop. of equality

• Multiplicaion prop. of equality

• Dividion prop. of equality 

Multiple Choice

What property of equality would you use to solve this equation in the first step.

 $-4\left(x+3\right)=-5$  

• Addition prop. of equality

• Subtraction prop. of equality

• Multiplicaion prop. of equality

• Dividion prop. of equality 

Poll

Can you solve the equation by adding 3 before multiplying by 5?

 $\frac{d-3}{5}=6$  

• Yes

• No

Poll

Do you feel like to you are understanding this lesson?

• Yes

• No

• Maybe with practice

• I need help ASAP