Whenever you solve a one-step equation you are finding the value of the variable. The key to solving one-step equations with addition and subtraction is, that whatever operation you perform on one side of the equation, you must also perform on the other side of the equation.

In order to isolate your variable you will perform an “Inverse Operation” which means if you have an addition operation, the “inverse operation” is subtraction. Let’s look at some examples of one-step equations.

One-step equations example problems

Example 1. One-step equation with subtraction

X – 5 = 7
Step 1 In order to isolate the variable ( X ) add 5 to both sides
X – 5 + 5 = 7 + 5
Step 2. x = 12
 
Example 2.
x -2 = (-10 )
 
Step 1. In order to isolate the variable add 2 to both sides
x -2 + 2 = (-10 ) + 2
Step 2 x = -8
 
Example 3
This one-step equation involves the addition
x+4 = 10
   -4     -4
x= 6
 
Example 4
x-5.5 =    10
  +5.5 = +5.5
x = 15.5
 
Example 5
14 = y-3
+3 =  +3
​17 = y
 
 

These videos may help with one-step equations.