1. Section 2.5 Solving Equations by Adding or Subtracting
Algebra Concepts
Section 2.5
Solving Equations by Adding or Subtracting

2. When you solve for the variable in an equation, you “unwrap” the variable
You want the variable alone on one side of the equation.

3. “Undo” operations with the variable.
Addition undoes subtraction.
Subtraction undoes addition
There are called inverse operations!

5. Math hymn
What so ever you do to the left of the equation, that you do unto the right!

6. Think of the equation as a seesaw
Think of the equation as a seesaw. It starts balanced and you have to keep it balanced.

7. Draw a line down from the equal sign. Never do something to only side
Draw a line down from the equal sign. Never do something to only side! It will become unbalanced.

9. Solve for the variable.
Substitute the solution
into the ORIGINAL
equation
It should make a true
sentence.
CHECK IT!

10. Try these!
Solve ALGEBRAICALLY and check #1 𝑚−10=15 #2 𝑥+ −10 =4 #3 22=𝑥+5 #4 𝑞− −24 =12 #5 −15=𝑟−2