Writing Equations

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

Samuel bought 3 tires for $79.95 each and some rims for $59 each. He spent a total of $534.85. Which equation could be used to find the number of rims, r, Samuel bought?

• 3(79.95) - 59r = 534.85
• 79.95r - 59(3) = 534.85
• 3(79.95) + 59r = 534.85
• 79.95r + 59(3) = 534.85

What is the first step to solve this equation 2x + 11 = 23?

• Add 3 to both sides
• Subtract 11 from both sides
• Add 1 to both sides
• Divide 3 on both sides

2. Cheryl gets paid $8 per hour for her job at the record store.  She made a total of $96 last week.  Which equation models this situation?

• 96h = 8
• h/96 = 8
• 8h = 96
• h/8 = 96

Pizzazz Publications is having some books printed. The printer charges $800 plus $5 per book. What equation could help me find how many books can be printed for $4,000?

• 800 + 5x = 4000
• 800x + 5 = 4000
• 4000 + 5x= 800
• 800 + 5 = 4000

The space club is having some posters printed. The printer charges $250 plus $2 per poster. How can I figure out how many posters I could print for $1,000?

• 250x + 2 = 1000
• 1000 + 2x = 250
• 250 - 2x = 1000
• 2x + 250 = 1000

Three desks and a bookcase together weigh 157 pounds. The bookcase weighs 34 pounds. Which equation could help me find out how much each desk weighs?

• 34 + 3 = 157
• 34x + 3 = 157
• 3x + 34 = 157
• x + 34 = 157

Oshgosh would like to buy a new pair of skates for $115. So far he has saved $40. If he earns $7.50 per hour, how could I find out how many hours he must work in order to buy the skates?

• 40 + 7.50x = 115
• 40x + 7.50 = 115
• 40 + 7.50 = 115
• 40 + 17.50x = 115

Mr. Piper's plumbing needed repairs. The plumber charged $98 for parts plus $45 per hour for labor. If the bill totaled $458, how could I find out the hours of labored required?

• 98x + 45 = 458
• 98 + 45x = 458
• 45 + 98 = 458
• 45x - 98 = 458

The space club is having some posters printed. The printer charges $250 plus $2 per poster. How can I figure out how many posters I could print for $1,000?

• 250x + 2 = 1000
• 1000 + 2x = 250
• 250 - 2x = 1000
• 2x + 250 = 1000