Solving for a Variable on Both Sides

Select the situation that could be modeled by: 120 + 25x = 45x.

• John bought a car radio for $120 and speakers for $25 each. Joe bought a radio for $45. They each paid the same. How much did they spend?

• George charges a flat fee of $120 to mow a lawn plus $25 an hour. Greg charges $45 a hour to mow a lawn. After how many hours do they make the same amount?

• Lisa pays $120 for each purse she buys plus an additional $25 to have them personalized. Lauren pays $45 for each purse she buys. How many purses must they buy for the amount they spent to be the same?

Put the Steps or solving Equations with Variables on both sides in order.

• Move the variables to one side

• Distribute

• + or - the constant

• Combine Like terms

• -6=3x-9

• 2x-6=5x-9

• 1=x

• 3=3x

Tags

CCSS.8.EE.C.7B

Solve the equation for d. 
d / t = r

• d = r / t

• d = t / r

• d = rt

• d = r - t

Tags

CCSS.HSA.CED.A.4

Solve for the variable.

22+2a=37+6+a

• a = 21

• a = 5

• a = -5

• a = -16

Solve for the variable.

8-3a+12=2a

• a = 4

• a = 1

• a = 3

• a = 5

Tags

CCSS.7.EE.B.4A

Solve for the variable.

10x + 9 = 4x - 9

• x = 18

• x = 3

• x = -3

• x = -18

f - 4 = 6f + 26

• f = -5

• f = 5

• f = 6

• f = -6

10x + 9 = 4x - 9

• 0

• 3

• -3

• -18

-5k + 10 = -2k - 14

• 8

• -8

• 2

• -2