Writing Equations and Inequalities

A local bakery has a daily operating cost of $1800 plus a cost of $10 per cake they make. If a cake sells for $15, which equation could be used to determine the minimum number of cakes, c, they must sell each day to earn a profit?

• 15c < 1800 + 10c

• 15c > 1800 + 10c

• 15c = 1800 + 10c

• 10c < 1800 + 15c

Tags

CCSS.7.EE.B.4B

At the beginning of the year, Ethan has $800 in his savings account and Faith has $1,280 in her savings account.  Each month, Ethan deposits and additional $25 in his account, while Faith withdraws $15 from her account.  Write an equation to show after how many months will Ethan’s account have a greater balance than Faith’s account?

• 800 - 25x  < 1280 - 15x
• 800 + 25x < 1280 - 15x
• 800 + 25x  > 1280 - 15x
• 800 + 25x >  1280 + 15x

Tags

CCSS.7.EE.B.4B

Sue's lunch account has $25 and she spends $2.50 every day. Troy's lunch account has $50 and she spends $3.25 every day. Write an inequality that shows when Sue's account will be more than Troy's.

• 25 - 2.5d > 50 - 3.25d
• 25 - 2.5d < 50 - 3.25d
• 25 + 2.5d > 50 + 3.25d
• 25 + 2.5d < 50 + 3.25d

Tags

CCSS.6.EE.B.5

CCSS.6.EE.B.6

CCSS.6.EE.B.8

CCSS.6.EE.C.9

Which situation can be represented by the equation 
1500 - 50x = 2000 - 100x

• There are two water tanks in the city.  One tank has 1500 gallons and gains 50 gallons each hour.  The other tank has 2000 gallons and gains 100 gallons each hour.  When will the tanks have the same amount of water?
• There are two water tanks in the city.  One tank has 1500 gallons and loses 50 gallons each hour.  The other tank has 2000 gallons and gains 100 gallons each hour.  When will the tanks have the same amount of water?
• There are two water tanks in the city.  One tank has 1500 gallons and loses 50 gallons each hour.  The other tank has 2000 gallons and loses 100 gallons each hour.  When will the tanks have the same amount of water?
• There are two water tanks in the city.  One tank has 1500 gallons and loses 50 gallons each hour.  The other tank has 2000 gallons and loses 100 gallons each hour.  When will the bigger tank have more water?

Tags

CCSS.6.EE.B.5

CCSS.6.EE.B.6

CCSS.6.EE.B.7

CCSS.6.EE.C.9

The table shows the cost per month of two cell phone plans. Which inequality can help determine how many phone calls you need to make per month so that Plan 2 is a better option?

• 25 - 0.35n > 37 - 0.25n

• 0.35n + 25 > 0.25n + 37

• 25 - 0.35n < 37 - 0.25n

• 0.35n + 25 < 0.25n + 37

Tags

CCSS.7.EE.B.4B

Veronica is ordering trophies for her school. Company P charges $3.50 for each trophy and a one-time engraving fee of $25. Company R charges $7.50 for each trophy and a one-time engraving fee of $17. Which inequality can be used to find x, the minimum number of trophies that can be ordered so that the total charge at company P is less than the total charge at Company R?

• 3.5 + 25x < 7.5 + 17x

• 3.5 + 25x > 7.5 + 17x

• 3.5x + 25 < 7.5x + 17

• 3.5x + 25 > 7.5x + 17

Tags

CCSS.7.EE.B.4B

The temperature in the ice rink must stay below 50°F. This morning, the temperature was 71°F. The ice rink runs a cooling device that can decrease the temperature by 3.5° every hour. Which inequality shows how long it will take for the temperature to fall below 50°F?

• 50 + 3.5x < 71
• 71 - 3.5x < 50
• 71 - 3.5x ≤ 50
• 71 + 3.5x < 50

Tags

CCSS.6.EE.B.5

CCSS.6.EE.B.6

CCSS.6.EE.B.8

The vet told Casey that her dog should weigh at most 70 lbs. Her dog weighs 106 pounds, so Casey set a goal that he would lose 4 pounds per week. Which inequality represents the number of weeks it take for Casey's dog to reach 70 lbs?

• 106 - 4x ≤ 70
• 70 + 4x ≤ 106
• 4x - 106 ≥ 70
• 106 - 4x< 70

Tags

CCSS.7.EE.B.4B

The members of Indian Spring Middle School's cheerleaders need to raise at least $2000 to attend their national competition. They raised $300 with their last fundraiser and decide to host a school talent show to raise the rest. They plan to charge $10 for each ticket. Which inequality shows the number of tickets they must sale to reach their goal?

• 300x + 10 ≥ 2000

• 10x + 300 ≤ 2000

• 10x + 300 > 2000

• 300 + 10x ≥ 2000

Tags

CCSS.7.EE.B.4B

Juan bought a soda for $2. He also bought some nachos for $3 each. Juan did not spend more than $14 on the nachos and the soda. Write an inequality can be used to find n, the number of nachos that Juan could have bought.

• 14 ≥ 2n+3

• 2+3n ≤ 14

• 14-3n ≤ 2

• 14x+2 ≤ 3

Tags

CCSS.7.EE.B.4B