Riley solved an equation, as shown in the table.

\begin{tabular}{|c|r|}
\hline Step & Statement \\
\hline 1 & [tex]$-2x + 4 = 3$[/tex] \\
\hline 2 & [tex]$-2x + 4 - 4 = 3 - 4$[/tex] \\
\hline 3 & [tex]$-2x = -1$[/tex] \\
\hline 4 & [tex]$\frac{-2x}{-2} = \frac{-1}{-2}$[/tex] \\
\hline 5 & [tex]$x = \frac{1}{2}$[/tex] \\
\hline
\end{tabular}

Which statement is true?

A. Riley made a mistake in step 2.
B. Riley made a mistake in step 4.
C. Riley made a mistake in step 5.
D. Riley solved the equation correctly.



Answer :

Let's carefully analyze each step of the solution provided by Riley, ensuring that no mistakes are made:

1. Step 1: [tex]\( -2x + 4 = 3 \)[/tex]
This is the original equation.

2. Step 2: [tex]\( -2x + 4 - 4 = 3 - 4 \)[/tex]
[tex]\( -2x = -1 \)[/tex]
Riley correctly subtracted 4 from both sides to isolate the term involving [tex]\( x \)[/tex]. So far, this step is correct.

3. Step 3: [tex]\( -2x = -1 \)[/tex]
This is a simplified version of the previous step, and it is correctly copied.

4. Step 4: [tex]\( \frac{-2x}{2} = \frac{-1}{2} \)[/tex]
Here Riley made a mistake. When dividing by the coefficient of [tex]\( x \)[/tex], which is -2, the correct division should be:
[tex]\[ \frac{-2x}{-2} = \frac{-1}{-2} \][/tex]
Simplifying, we get:
[tex]\[ x = \frac{-1}{-2} = \frac{1}{2} \][/tex]

Riley incorrectly divided by 2 instead of -2, leading to an incorrect value for [tex]\( x \)[/tex].

5. Step 5: [tex]\( x = -\frac{1}{2} \)[/tex]
Based on the incorrect division in Step 4, Riley arrived at the wrong solution.

Therefore, Riley made a mistake in Step 4. The corrected value for [tex]\( x \)[/tex] should be [tex]\( \frac{1}{2} \)[/tex].

So, the correct statement is:
- Riley made a mistake in step 4.