Compare Solution Methods for Multi-Step Equations Quick Check 1 of 51 of 5 Items Question One method for solving 3(x−4)=18 is to first divide by 3, then add 4. Which method below would also result in the correct answer?(1 point) Responses First, multiply by 13, then subtract 4. First, multiply by Start Fraction 1 over 3 End Fraction , then subtract 4. First, distribute the 3, then add 4, and lastly divide by 3. First, distribute the 3, then add 4, and lastly divide by 3. First, divide by 3, then subtract 4. First, divide by 3, then subtract 4. First, distribute the 3, then add 12, and lastly divide by 3..

1 answer

To solve the equation \(3(x-4) = 18\), we can explore different methods that will lead to the correct answer.

  1. The original proposed method involves first dividing by 3, then adding 4: \[ x - 4 = \frac{18}{3} \Rightarrow x - 4 = 6 \Rightarrow x = 6 + 4 \Rightarrow x = 10. \]

Let's analyze the other methods provided:

  • First, multiply by 13, then subtract 4.

    • This is not a valid operation in this context and would not yield the correct result.
  • First, multiply by \( \frac{1}{3} \), then subtract 4.

    • This method would first change the equation to \( x - 4 = 6 \), leading to the wrong results, as multiplying the entire equation by \( \frac{1}{3} \) is not appropriate.
  • First, distribute the 3, then add 4, and lastly divide by 3.

    • Distributing the 3 first yields \( 3x - 12 = 18 \). Adding 4 results in \( 3x - 8 = 18 \), and then dividing by 3 would lead to \( x - \frac{8}{3} = 6 \), which is incorrect.
  • First, distribute the 3, then add 4, and last divide by 3.

    • This is essentially the same as the previous method phrased differently and would also lead to a wrong direction.
  • First, divide by 3, then subtract 4.

    • This accurately reflects the original proposed method but does not yield new insights.
  • First, distribute the 3, then add 12, and lastly divide by 3.

    • Distributing gives \( 3x - 12 = 18 \). Adding 12 results in \( 3x = 30 \), and dividing by 3 gives us \( x = 10 \), which is correct.

Thus, the method that also results in the correct answer is: First, distribute the 3, then add 12, and lastly divide by 3.