Which expressions are equivalent to -9 (2/3x + 1)? Check the two that apply.

A. -9 (2/3x) + 9 (1)
B. -6x + 1
C. -9 (2/3x) - 9 (1)
D. -6x - 9
E. -6x + 9

1 answer

To find the expressions equivalent to \(-9 \left(\frac{2}{3}x + 1\right)\), we will distribute \(-9\) to both terms inside the parentheses:

\[ -9 \left(\frac{2}{3}x + 1\right) = -9 \cdot \frac{2}{3}x - 9 \cdot 1 \]

Calculating the first term: \[ -9 \cdot \frac{2}{3}x = -6x \]

Calculating the second term: \[ -9 \cdot 1 = -9 \]

Putting it all together, we get: \[ -9 \left(\frac{2}{3}x + 1\right) = -6x - 9 \]

Now we’ll compare this result with the given options:

A. \(-9 \left(\frac{2}{3}x\right) + 9 \left(1\right)\)

  • This simplifies to \(-6x + 9\), not equivalent.

B. \(-6x + 1\)

  • This does not match, not equivalent.

C. \(-9 \left(\frac{2}{3}x\right) - 9 \left(1\right)\)

  • This simplifies to \(-6x - 9\), equivalent.

D. \(-6x - 9\)

  • This matches our result, equivalent.

E. \(-6x + 9\)

  • This does not match, not equivalent.

The two expressions that are equivalent to \(-9 \left(\frac{2}{3}x + 1\right)\) are:

C. -9 (2/3x) - 9 (1) and D. -6x - 9.