Inverse Operation

Addition and Subtraction

The Goal of an algebraic equation is to find the value of the variable.

• The inverse operation of addition is subtraction

• The inverse operation of subtraction is addition

  When you see an addition sign be sure to subtract!

  And when you see a subtraction sign be sure to add!

Add

X + 5 = 8

-5 -5

0 3

When you subtract the constant by the answer you have the variable. you also have to subtract the other side of the equation to balance it.

in order to check your work put the number in place of the variable and do the problem as follows.

If your answer remains the same as the original you are correct!

8

8 = 8

X = 3

​3 + 5 = _

W - 8 = 5

+ 8 +8

16 13

5 = 5

W = 13

​13 - 8 = _

5

When you add the constant to the answer you are left with the variable. You also have to add the the other side of the equation to balance it.

in order to check your work put the number in place of the variable and do the problem as follows.

If your answer remains the same as the original you are correct!

​ Subtract

Multiplication and Division

The Goal of an algebraic equation is to find the value of the variable.

• The inverse operation of multiply is divide

• The inverse operation of subtract is multiply

  When you see a multiplication sign be sure to divide!

  And when you see a Division sign be sure to multiply!

Multiply

y x 6 = 12

÷6 ÷6

1 2

When you divide the constant from the answer you have the variable. you also have to divide the other half of the equation to balance it.

in order to check your work put the number in place of the variable and do the problem as follows.

If your answer remains the same as the original you are correct!

12

12 = 12

y = 2

​2 x 6 = _

b ÷ 10 = 2

x10 x 10

100 20

2 = 2

b = 20

​20 ÷ 10 = _

2

When you multiply the constant by the answer you have the variable. you also have to multiply the other half of the equation to balance it.

in order to check your work put the number in place of the variable and do the problem as follows.

If your answer remains the same as the original you are correct!

​Divide