Writing Equations from Situations

Jenny charges $10 to babysit, plus $7.50 per hour she's there.  Write an equation for the cost, C, she charges for working h hours.

• C=10h+7.50

• C=10+7.50h

• C=7.50+10h

Tags

CCSS.8.F.B.4

CCSS.HSF.LE.A.2

A lake is evaporating due to a drought.  It began as being 28 ft deep at it's lowest point, but has been getting more shallow by 0.25 ft per week.  Write an equation for the water level, L, after w weeks.

• L=28-0.25w

• L=28+0.25w

• L=0.25+28w

• L=0.25-28w

Tags

CCSS.HSF-BF.A.1A

A grain silo sits empty.  It begins filling with barley at a rate of 8lbs per second when the train brings a shipment.  Write an equation for the amount of grain, G, after s seconds.

• G=0+8

• G=0+8s

• G=8s

• G=-8s

Tags

CCSS.HSF-BF.A.1A

Dairy queen's ice cream machine has a volume of 64 cups of soft-serve mix when full.  Each Blizzard uses 0.4 cups of mix.  Write an equation for the amount of ice cream mix left, M, after making b Blizzards.

• M=0.4+64b

• b=64-0.4M

• M=64-0.4b

Tags

CCSS.HSF-BF.A.1A

The population of Billings was 117,000 in 2021.  On average, it is growing by around 2,000 each year.  Write an equation to represent the population, P, for the y years.

• y=117,000+2,000x

• P=117,000+2,000y

• P=2000y-117,000

Tags

CCSS.HSF-BF.A.1A

A plumber charges $90 to go to a home for a service call, then charges an additional $55 per hour of work.  Write an equation for their cost, C, for the number of hours, h, worked.

• C=90+55h

• h=90+55C

• C=55+90h

Tags

CCSS.HSF-BF.A.1A

A ticket to Disneyland costs $145 and you can expect to spend around $9.00 for each snack while at the park.  Write an equation for your total expenses, E, based on the number of snacks, s, you purchase.

• E=145+9.00s

• E=9.00+145s

• S=145-9.00e

Tags

CCSS.HSF-BF.A.1A

A 3-wick candle from Bath & Bodyworks is 7.5 inches tall when purchased.  Each hour it burns, it melts 0.2 inches.  Write an equation for the height of the candle, C, after h hours. 

• C=0.2h-7.5

• C=7.5+0.2h

• C=7.5-0.2h

Tags

CCSS.HSF-BF.A.1A

A rental car company charges $48 for each day that you rent a vehicle, plus $0.05 per mile.  Write an equation for the price you will pay, P, after m miles.

• P=48+0.05m

• P=48-0.05m

• P=0.05+48m

Tags

CCSS.8.F.B.4

CCSS.HSF.LE.A.2

Casey is draining her pool for the winter.  It beings with a volume of 20,000 gallons of water and can be drained at a rate of 12 gallons per minute.  Write an equation for the volume of the pool, V, after m minutes.

• M=20,000+12v

• V=20,000-12m

• V=20,000+12m

Tags

CCSS.HSF-BF.A.1A