If you have an equation with addition or subtraction, you can apply the inverse operation to both sides of the equation to get the variable alone. Addition and subtraction are inverse operations.
Let's try it. Solve The equation has subtraction. Use the inverse operation, addition. Add 19 to both sides of the equation.
Add 19 to both sides of the equation.
You can check your solution. Take the original equation, and replace the variable with your solution. If that equation is true, your solution is correct!
This is true, so is the solution. 51
This is true, so is the solution. Let's try it for another example. Solve Use the inverse operation, subtraction. Subtract 48 from both sides of the equation.
Subtract 48 from both sides of the equation.
Check your solution. Take the original equation, and replace the variable with your solution. If that equation is true, your solution is correct.
This is true, so is the solution. 71
This is true, so is the solution. 
