Question

Which property justifies the work between steps 7 and 8

Answer 1

The property that justifies the work between steps 7 and 8 is the identity property of addition.

It states the following:

`\begin{gathered} a+0=a \\ 0+a=a \end{gathered}`

That is, when we have any expression added to zero, the result is the same expression.

So, from step 7 to 8, we can use the property to edit the left side of the equation:

`6x+0=6x`