Writing Equations

The baby giraffe weighed 132 pounds at birth. He gained weight at a steady rate for the first 7 months until his weight reached 538 pounds. How much did he gain each month? Which equation represents the situation?

• 538 + 7x = 132

• 7(x+132) = 538

• 7x - 132 = 538

• 132 + 7x = 538

The sum of fourty-one and fifteen

• 41- 15

• 41x15

• 41= 15

• 41 + 15

Speedy Boat Rental charges a $15 deposit fee plus $2 for each hour of use to rent a paddle boat.  Write an equation to find out how many hours, h, they rented the Boat if the total cost was $33.

• h = 2(9) + 15
• 33 = 15h + 2
• h = 15(9) + 2
• 33 = 2h + 15

17 less than 59

• 17-59

• 59-17

• 59+17

• 17+59

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

Casey has $50 to spend at Best Buy. She wants to buy a DVD for $14 and some CDs that cost $12 each. How many CDs can she buy?

• 12 + 14x = 50

• 12x + 14 = 50

• 50 - 14 - 12 = x

• 50x + 12 = 14

A club puts its members into 5 groups for an activity. After 7 students have to leave early, there are only 3 students left to finish the activity. How many students were in each group?

• 5x - 7 = 3

• 3(x + 5) = 7

• 3x + 5 = -7

• 1/3(x + 7) = 5

Six teams are out on the field playing soccer. The teams all have the same number of players. The head coach asks for 2 players from each team to come help him move some equipment. Now there are 78 players on the field. Write an equation to represent the situation.

• 6x - 2 = 78

• 6(x+2) = 78

• 6(x-2) = 78

• 78/6 - 2

Clare ran 4 miles on Monday. Then for the next six days, she ran the same distance each day. She ran a total of 22 miles during the week. How many miles did she run on each of the 6 days? Which equation represents the situation?

• 22 - 4/6

• 4(x + 6) = 22

• 4x + 6 = 22

• 6x + 4 = 22

Six decreased by twice a number.

• 2x - 6

• 6 < 2x

• 6 - x

• 6 - 2x