Adding and Subtracting Equations

What step can be taken to get the x by itself on one side in the equation x + 18 = 50 ?

• Multiply both sides of the equation by 18

• Divide both sides of the equation by 18

• Add 18 to both sides of the equation

• Subtract 18 from both sides of the equation.

a - 17 = 9

• a = 36

• a = 14

• a = 26

• a = 32

57 + c = 93

• c = 37

• c = 97

• c = 36

• c = 27

y - 4.6 = 12

• 16.6

• 5.8

• 7.4

• Answer not Given

m - 12 = 25

• -37

• 13

• -13

• 37

9.5 + x = 14.2

• 4.7

• 23.7

What equation matches this situation?
John wants to buy an MP3 Player that costs $30.98.  How much change did he receive if he gives the cashier $40.

• 40 + c = 30.98

• 30.98 + c = 40

• c - 40 = 30.98

• c - 30.98 = 40

Samuel bought a tire for $79.95 and some rims. He spent a total of $534.85. Which equation could be used to find the cost of the rims, r, Samuel bought?

• 79.95 - r = 534.85

• r - 79.95 = 534.85

• r + 79.95 = 534.85

• 534.85 + 79.95 = r

On his lunch break, Crosby purchases a piece of pizza for $6.30 and a salad. The total order is $9.25. Which equation could be used to find the cost of the salad?

• x + 6.30 = 9.25

• x - 6.30 = 9.25

• x + 9.25 = 6.30

• x - 9.25 = 6.30

According to CBS, in 2000 the average cost of a World Series ticket was $450. This is $180 more than the cost of a 2007 ticket. Which equation can be used to find how much the ticket was in 2007?

• x + 2000 = 2007

• 2007 - 2000 = x

• x - 180 = 450

• x + 180 = 450