Addition Problems To solve equations, the general rule is to do the opposite. For example, consider the following example. Example `x+7=−5`

`x+7=−5`	The 7 is added to the `x`
`x+7color(red)(-7)=−5color(red)(-7)`	Subtract 7 from both sides to get rid of it
`x = − 12`	Our solution

Then we get our solution, `x = − 12`. The same process is used in each of the following examples. Subtraction Problems In a subtraction problem, we get rid of negative numbers by adding them to both sides of the equation. For example, consider the following example. Example `x − 5 = 4`

`x − 5 = 4`
`x − 5 color(red)(+5)= 4 color(red)(+5)`	Add `5` to both sides
`x=9 `	Solution!

Then we get our solution `x = 9`. The same process is used in each of the following examples. Notice that each time we are getting rid of a negative number by adding.