Question

Explain two ways you could solve 20= 5(-3+x)

Answer 1

First way. Distribute the 5 first.

In this way, we first remove the parentheses and isolate x later

By multipliying 5 by the term into the parentheses, we get

`\begin{gathered} 20=5(-3)+5\cdot x \\ 20=-15+5x \end{gathered}`

Now, if we move -15 to the left hand side as +15, we have

`20+15=5x`

which gives

`\begin{gathered} 35=5x \\ (35)/(5)=x \\ x=7 \end{gathered}`

that is, x is equal to 7.

Second way. Divide by 5 first

In this way, we first move 5 to the left hand side and isolate x later

If we move 5 to the left hand side, we have

`(20)/(5)=-3+x`

which gives

`4=-3+x`

if we move -3 to the left hand side as +3, we obtain

`\begin{gathered} 4+3=x \\ 7=x \end{gathered}`

so, we obtain the same result, x=7.