To solve the equation \( 3(x - 4) = 18 \), we can use the original method of dividing by 3 and then adding 4:
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Divide both sides by 3: \[ x - 4 = \frac{18}{3} \] \[ x - 4 = 6 \]
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Add 4 to both sides: \[ x = 6 + 4 \] \[ x = 10 \]
Let's analyze the other options to see which one would also result in the correct answer.
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First, multiply by 13, then subtract 4.
This method does not maintain the equality correctly and does not solve for \( x \). (Not correct) -
First, multiply by \(\frac{1}{3}\), then subtract 4.
Similar to the first one, this does not maintain the equality correctly in the second step. (Not correct) -
First, divide by 3, then subtract 4.
If you divide by 3, you get \( x - 4 = 6 \), and then subtracting 4 gives: \[ x - 4 - 4 = 6 - 4 \Rightarrow x - 8 = 2 \] This does not give the correct solution. (Not correct) -
First, distribute the 3, then add 12, and lastly divide by 3.
Distributing gives \( 3x - 12 = 18 \). Adding 12 gives \( 3x = 30 \). Finally, dividing by 3 gives \( x = 10 \). (Correct) -
First, distribute the 3, then add 4, and lastly divide by 3.
Distributing gives \( 3x - 12 = 18 \). Adding 4 gives: \[ 3x - 8 = 18 \] This does not lead to the right answer. (Not correct)
Thus, the correct alternative method that results in the correct answer is:
First, distribute the 3, then add 12, and lastly divide by 3.