Writing Inequalities #1

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

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

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

17. 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

• 25 - 0.35n < 37 - 0.25n

• 0.35n + 25 > 0.25n + 37

• 0.35n + 25 < 0.25n + 37

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

• 3.5x + 25 < 7.5x + 17

• 3.5 + 25x < 7.5 + 17x

• 3.5x + 25 > 7.5x + 17