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Yusuf tried to solve an equation step by step. \[\qquad\begin{aligned} \dfrac{1}4r+2&=10\\\\ \\ \dfrac{1}4r&=12&\green{\text{Step } 1}\\\\ \\ r&=48&\blue{\text{Step } 2}\\\\ \end{aligned}\] Find Yusuf's mistake.

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Answer:

Yusuf's mistake is in Step 1 of his solution.

Yusuf incorrectly added 2 to both sides of the equation, instead of subtracting it.

The correct step would be to subtract 2 from both sides:

\(\frac{1}{4}r + 2 - 2 = 10 - 2\)

Simplified into:

\(\frac{1}{4}r = 8\)

By changing the addition to subtraction, the equation would have been correctly set up for further solving.

The correct solution is \(r = 32\).

Explanation:

Given: \(\frac{1}{4}r + 2 = 10\)

Steps:

Step 1: Subtract 2 from both sides of the equation to isolate the term with "r":

\(\frac{1}{4}r = 10 - 2\)

Simplifying:

\(\frac{1}{4}r = 8\)

Step 2: Solve for "r" by multiplying both sides by 4 to eliminate the fraction:

\(4 \cdot \frac{1}{4}r = 4 \cdot 8\)

Simplifying:

\(r = 32\)

Conclusion: Yusuf's mistake was adding 2 instead of subtracting it in Step 1. By subtracting, we correctly obtain the solution \(r = 32\).

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