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

User Alones
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1 Answer

22 votes
22 votes

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.

User Ozkar
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