Solving Two-Step Equations

Writing Two Step Equations

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Multiple Choice

DO NOW

7(9 + K)= 84
k =____________

• 3
• -3
• 5

I DO: Writing two step equations

Valery had $15. She wanted to purchase some headphones that were $75. If she saves $3 a week from her chores, how long will it take her to reach her goal?

I DO: Writing two step equations
David had $255. If he goes below the balance of 25 then he gets charged each day it is below. He spends $10 a day on lunch. How many days until can he do this before he gets charged?

WE DO: Writing two step equations
Mark's goal was to save $150. He owes his mom $30 and he makes $10 per hour tending to the bulls. How many hours will he need to work to reach his goal?

Reminder! Watch out for negatives!

• debt, withdrawal, take away

Multiple Choice

WRITE AN EQUATION
April had $24 to spend on seven pencils. After buying them she had $10. How much did each pencil cost?

• n=total cost pencils; 7n+10=24
• n=cost of 1 pencil; 7n-10=24
• n=cost of 1 pencil; 7n+10=24
• n=cost of 1 pencil; -7n-10=24

Writing Equations- White Boards

A one year membership to Metro Gym costs $460. There is a one time fee of $40 when you join, and the rest is paid monthly. Write an equation to represent the situation that can help members find how much they per per month.

One time joining fee of $40 Plus 12 times months equals $460

Multiple Choice

Which equation matches the following situation? 331 students went on a field trip. Six buses were filled and 7 students traveled in cars. How many students were in each bus?

• 6n + 7 =331

• 6n + 7 =331

• 6 + 7n =331

• 6n - 7 =331

Writing Equations- White Boards

Madison has $50 saved from her birthday. She plans to save an additional 10 each week. How long will it take her to save a total of $100? Write an equation that represents this saving plan.

Multiple Choice

A cell phone company charges $3.00 to make a phone call plus $0.15 for each minute for each minute you talk. Which equation would you use to determine the total cost, c, of a phone call that is m number of minutes long?

• c = 3.00 - 0.15m
• c = 0.15 + 3.00m
• 3.00 = c + 0.15
• c = 3.00 + 0.15m

Poll

Billy has a gift card with $150 balance. He buys several video games that cost $35 each. After the purchases, his gift card balance is $45. Write an equation to help find out how many video gams Billy bought. (Find the solution)

• 150 - 45v = 35

• 150 - 35v = 45

Multiple Choice

Casey has $50 to spend at Best Buy. She wants to buy a DVD for $14 and some CDs that cost $12 each. How many CDs can she buy?

• 12 + 14x = 50

• 12x + 14 = 50

• 50 - 14 - 12 = x

• 50x + 12 = 14

Poll

A restaurant sells a coffee refill mug for $6.75. Each refill cost $1.25. Last month Myles spent $31.75 on a mug and refills. Write an equation you can use to find the number of refills that Myles bought.

Hint:

price of mug + amount per refill times the number of refills equals total amount.

• 1.25 + 6.75r=31.25

• 6.75 + 1.25r=31.25

Multiple Choice

Write an equation for the following:

Twice a number plus 6 is -72

• 2 + 6x =- 72

• 2x + 6 = -72

• 2 + 6 = x

• 2x² + 6 = 72

Poll

Val rented a bike while she was on vacation. She paid a flat fee of $55 plus $8.50 each day. The total cost was $123. Write an equation you can use to find the number of days she rented the bike.

• 55-9d=123

• 55+8.50d=123

• 55d + 8.50 = 123

Multiple Choice

A banana has 85 calories. This is 10 calories less than one eighth of the calories in a banana split. Which equations helps you find how many calories are in a banana split?

• 85 - 10 = x
• x/8 + 10 = 85
• x/8 - 10 = 85
• x/8 - 10 = 75

Multiple Choice

Ken is thinking of a number. Nine more than the product of 4 and the number is 73. What is the equation?

• 4 + 9x = 73
• 4x = 73
• 4x + 9 = 73
• 9x + 4 = 73

Multiple Choice

Speedy Boat Rental charges a $15 deposit fee plus $2 for each hour of use to rent a paddle boat.  Write an equation to find out how many hours, h, they rented the Boat if the total cost was $33.

• h = 2(9) + 15
• 33 = 15h + 2
• h = 15(9) + 2
• 33 = 2h + 15

Multiple Choice

Figure out the solution to this equation: -4x + 1 = 21

• x = 120
• x = 5
• x = 30
• x = -5