Applications of Equations

The objective when solving an equation is to....

• isolate the variable

• check the solution

• guess and check

• combine like terms.

What what is the inverse operation of subtraction?

• addition
• subtraction
• multiplication
• division

What is the inverse operation of division?

• Division
• Multiplication
• Addition
• Subtraction

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.

Translate 4 more than x equals 7 into an equation and solve. 

• x+4=7
  x = 11
• x+4=7
  x = 3
• x-4=7
  x = 11
• x-4=7
  x=3

Which equation has x = 5 as the solution?

• x + 15 = 10
• 2x = 5
• 2x = 10

Solve the equation
3x = 27. 

• x = 24
• x = 81
• x = 9

Solve the equation:
20.5 = x + 4

• 16.5
• 16.05
• 24.5
• 24.05

Solve the equation:
x - 4 = 6

• x = 10
• x = -10
• x = 2
• x = -2

Solve for x:

• x = 20
• x = 7
• x = 10
• x = 3