Intro to Algebra/Geometry

Solving Equations by

Adding or Subtracting

Equations

• Equations use an = sign to show that two expressions are equal (balanced).

2 + 1 = 3 1+1 = 2

2 + x = 4

Variables

• A variable is a letter that represents a number.

• We can find what that number is.

• The solution of the equation is the value that can be substituted in for the variable to make an equation true.

Find the solution

1. 2 + x = 4

2. 3 - x = 1

Inverse Operation

Plus

Multiply

Minus

Divide

Minus

Divide

Plus

Multiply

Use Inverse Operations to Solve

1. x - 7 = 10

2. 5 + x = 25

3. 24 + x = 58

Remember

KEEP EQUATIONS BALANCED

WHATEVER YOU DO TO ONE SIDE OF THE EQUATION YOU HAVE TO DO TO

THE OTHER SIDE

Use Inverse Operations to Solve

1. x - 7 = 10

2. 5 + x = 25

3. 24 + x = 58