Solving Addition and Subtraction Equations Lesson 2-6

Procedure Isolate the variable by performing the inverse operation on that variable. The inverse of subtraction is adding. The inverse of adding is subtracting. Perform the same operation on the side of the equal sign that does not have a variable.

Example We want to get the y by itself. Perform the inverse operation. The inverse of adding is subtracting. y + 13 = 25 - 13 - 13 Do the same operation on the other side of the equal sign. y = 12

Check the answer in the original equation. y + 13 = 25 12 + 13 = 25 25 = 25

Example 2 To get k by itself, we perform the inverse operation. The opposite of “minus 12” is “plus 12.” k – 12 = 4 + 12 + 12 k = 16

Check k – 12 = 4 16 – 12 = 4 4 = 4

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