To solve the equation \( 3(x - 4) = 18 \), we can use different methods that manipulate the equation but still follow algebraic principles.
The original method you provided involves dividing by 3 first and then adding 4.
Let’s analyze each of the provided options:
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First, multiply by 13, then subtract 4.
- This is not correct because it does not maintain the equivalence of the equation.
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First, multiply by \( \frac{1}{3} \), then subtract 4.
- This is not correct because multiplying by \( \frac{1}{3} \) would give \( x - 4 = 6 \), and then subtracting 4 would not solve for \( x \) correctly.
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First, divide by 3, then subtract 4.
- This option essentially breaks down to the original method since it starts correctly with division, but the step of subtracting 4 instead of adding will give an incorrect result.
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First, distribute the 3, then add 12, and lastly divide by 3.
- Distributing gives \( 3x - 12 = 18 \), adding 12 gives \( 3x = 30 \), and then dividing by 3 gives \( x = 10 \). This method works.
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First, distribute the 3, then add 4, and lastly divide by 3.
- This option is incorrect because adding 4 after distributing will not give the correct result.
Thus, the correct answer is:
First, distribute the 3, then add 12, and lastly divide by 3.