Building Equations

*Lawrences's father gave him 200 baseball cards. Each week, Lawrence purchases 25 baseball cards to add to his collection.

Which inequality can be used to find w, the number of weeks after starting his collections when Lawrence will have more than 750 baseball cards in his collection?

Jeff bought a bottle of water for $2. He also bought some hot dogs for $3 each. Jeff did not spend more than $14 on the hot dogs and the bottle of water. Which inequality can be used to find h, the number of hot dogs that Jeff could have bought?

• 3h + 2 $\le$ 14

• Felicia has 12 buttons in her collection. She will collect 29 new buttons every year. Felicia collects buttons for k years. For what values of k will Felicia have at least 120 buttons? 

• Felicia has 29 buttons in her collection. She will collect 12 new buttons every year. Felicia collects buttons for k years. For what values of k will Felicia have at least 120 buttons? 

• Felicia has 29 buttons in her collection. She will collect 12 new buttons every year. Felicia collects buttons for k years. For what values of k will Felicia have at most 120 buttons? 

• Felicia has 12 buttons in her collection. She will collect 29 new buttons every year. Felicia collects buttons for k years. For what values of k will Felicia have at most 120 buttons? 

• Stefan spends $6.50 on supplies for a lemonade stand and sells each cup of lemonade for $1.25. What is x, the number of cups of lemonade Stefan must sell to earn a profit of more than $50?

• Stefan has a balance of $6.50 in his savings account and deposits $1.25 each week. What is x, the number of weeks Stefan must deposit $1.25 in order to have a balance of more than $50 in his savings account? 

• Stefan earns 1.25% interest on the balance in his checking account and has to pay a monthly charge of $6.50. What is x, the balance that Stephan must have in his checking account in order to have an ending balance greater than $50 after interest and fees?

• Stefan charges $1.25 for gasoline plus $6.50 per hour for mowing lawns. What is x, the number of hours he has to mow lawns to earn more that $50?

• Erica paid $753.95 for dance classes. She paid a $123.95 registration fee and $45 for each week she was enrolled in classes. What is w, the number of weeks Erica was enrolled in dance classes? 

• Erica paid $753.95 for dance classes. She paid a $45 registration fee and $123.95 for each week she was enrolled in classes. What is w, the number of weeks Erica was enrolled in dance classes? 

• Erica and her sister paid $753.95 for dance classes. Erica paid a $123.95 for each week she was enrolled in classes, and her sister paid $45 each week she was enrolled in the classes. What is w, the number of weeks Erica and her sister were enrolled in dance classes? 

• Erica paid $753.95 for dance classes. She paid a $123.95 for each week she was enrolled in the classes after using a coupon that gave her a $45 off the price per week. What is w, the number of weeks Erica was enrolled in dance classes? 

Walter and Brian each have a CD collection.

• The number of CDs in Walter's collection can be represented by x.
• The number of CDs in Brians collection is 3 times the number in Walter's collection.
• The total number of CDs in both collections is 144.

What is x, the number of CDs in Walter's collection?

• 108

• 48

• 72

• 36