Suzie solved the equation 9x-5=1/4(16x+60) using the following steps:

1) Distribute 1/4 to get 9x-5=4x+60
2) Use subtraction property of equality to move 4x to get 5x-5=60
3) Use addition property of equality to move 5 and get 5x=65
4) Use division property of equality to get x=13
Determine if Suzie solved correctly-if not, identify which step was the mistake.

1 answer

Let's go through Suzie's steps to see if she solved the equation correctly.

  1. The given equation is: \[ 9x - 5 = \frac{1}{4}(16x + 60) \] Distributing \(\frac{1}{4}\) on the right side: \[ \frac{1}{4}(16x) + \frac{1}{4}(60) = 4x + 15 \]

    So the equation should be: \[ 9x - 5 = 4x + 15 \] This means Suzie made a mistake in Step 1.

  2. Let's follow the corrected form of the equation: \[ 9x - 5 = 4x + 15 \] Next, we apply the subtraction property of equality to move \(4x\) to the left side: \[ 9x - 4x - 5 = 15 \] This simplifies to: \[ 5x - 5 = 15 \] (This part was done correctly in her Step 2.)

  3. Now, we will use the addition property of equality to move \(-5\): \[ 5x = 15 + 5 \] Which simplifies to: \[ 5x = 20 \] (This also implies she made a mistake in her Step 3.)

  4. Finally, we use the division property of equality: \[ x = \frac{20}{5} = 4 \] So the final solution is: \[ x = 4 \]

Thus, Suzie's final answer that \(x = 13\) is incorrect. The mistakes occurred in Step 1 (incorrect distribution) and subsequently in Step 3 (incorrect value carried over). The correct solution to the equation \(9x - 5 = \frac{1}{4}(16x + 60)\) is \(x = 4\).