In order to make the expression below equivalent to ½x + 6, which additional operation should be included in the expression?

5/4x + 6 +_
(1 point)
• -2x
•-x
3/4x
-3/4x

1 answer

To determine the additional operation that should be included in the expression \( \frac{5}{4}x + 6 + _\) so that it becomes equivalent to \( \frac{1}{2}x + 6 \), we can follow these steps:

  1. Write the two expressions we want to be equal: \[ \frac{5}{4}x + 6 + _ = \frac{1}{2}x + 6 \]

  2. Isolate the variable parts (remove the constant 6 from both sides): \[ \frac{5}{4}x + _ = \frac{1}{2}x \]

  3. Convert \( \frac{1}{2}x \) into a fraction with a denominator of 4 for easier comparison: \[ \frac{1}{2} = \frac{2}{4} \] So, \( \frac{1}{2}x = \frac{2}{4}x \).

  4. Rewrite the equation: \[ \frac{5}{4}x + _ = \frac{2}{4}x \]

  5. Now isolate \( _ \): \[ _ = \frac{2}{4}x - \frac{5}{4}x \]

  6. Perform the subtraction: \[ _ = \left( \frac{2}{4} - \frac{5}{4} \right)x = \frac{-3}{4}x \]

Thus, to make the original expression equivalent to \( \frac{1}{2}x + 6 \), the additional operation should be \( -\frac{3}{4}x \).

The correct answer is:

  • \(-\frac{3}{4}x\)