Question

Variables review find x if: x+7=20

Answer 1

There is a property called "Subtraction property of equality". This property states that, if:

`a=b`

Then:

`a-c=b-c`

In this case you have the following equation given in the exercise:

`x+7=20​`

So you need to solve for the variable "x" in order to find its value. To do that, you need to apply the Subtraction property of equality by subtracting 7 from both sides of the equation. Therefore, you get the following result:

`\begin{gathered} x+7-(7)=20​-(7) \\ x=13 \end{gathered}`

The answer is:

`x=13`