What is the value of F of 15 if F of X equals two-thirds X plus 14?

• A. 18
• B. 20
• C. 22
• D. 24

Answer: (D)

To determine the value of F at 15, we can substitute 15 into the function F(X) defined as ( F(X) = \frac{2}{3}X + 14 ).

First, replace X with 15 in the equation:

( F(15) = \frac{2}{3} \cdot 15 + 14 ).

Calculating ( \frac{2}{3} \cdot 15 ) gives:

( \frac{2 \cdot 15}{3} = \frac{30}{3} = 10 ).

Now add 14 to this result:

( 10 + 14 = 24 ).

Thus, ( F(15) = 24 ).

This confirms that the correct value of F at 15 is indeed 24.

The other options do not equal 24 when substituting the original expression. Therefore, they cannot be the value of F at 15. The calculation shows that the function properly accounts for both the multiplication and constant addition, leading us to the correct answer of 24.