Question

Andrea solves x + 19 = 31 and gets x = 50. She says she used theDo you agree with Andrea's answer and her reasoning? Explain.Addition Property of Equality because it is an addition equation.

Answer 1

Given the equation:

`x+19=31`

You need to solve for "x" in order to find its value.

In order to do this, you need to remember that Addition and Subtraction are Inverse Operations. Addition undoes the action of Subtraction and Subtraction undoes the action of Addition.

Since there is an Addition on the left side of the equation, where the variable is located, you need to apply the corresponding inverse operation on both sides of the equation in order to solve for "x".

According to the Subtraction Property of Equality, if:

`a=b`

Then:

`a-c=b-c`

Therefore, subtracting 19 from both sides of the equation, you get:

`\begin{gathered} x+19-(19)=31-(19) \\ x=12 \end{gathered}`

Hence, the answer is: No, I don't agree with Andrea and her reasoning, because Subtraction undoes the action of Addition. Therefore, she must use the Subtraction Property of Equality by subtracting 19 from both sides of the equation, in order to solve for "x".