Solve an Equation for a Given Variable

In the equation

x + 7 = 12

7 is being added to the variable, x.

How should you show your work to isolate the variable and solve the equation?

• Subtract 7 from both sides. The solution is x = 5.

• Add 7 to both sides.

  The solution is x = 19.

• Multiply both sides by 7 The solution is x = 84.

Is x=4 a solution to the equation 6 = x+2 ?

• Yes

• No

Each nickel is worth $0.05. 

Write an equation for the number of nickels when the total amount of money in nickels is $2.25.

• n = 2.25(0.05)

• 2.25n = 0.05

• 0.05n = 2.25

Solve the given equation.

62.52=27.39+t

Check your solution using substitution.

• t = 90.01

• t = 89.91

• t = 35.13

• t = 2.28

Solve for x using inverse operations.

25x = 75

• x = 100

• x = 4

• x = 3

• x = 50

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

Write an equation models the following statement:
 17 less than h equals 42

• 17-h=42

• h-17=42

• h+17=42

• 17+h=42

12x = 144

• x = 12

• x = 4

• x = 2

• x = 132

y + 8 = 20

• 10

• 11

• 12

• 13