r^2 - 3 / 4r when r = 3

Answer 1

To evaluate the expression \( \frac{r^2 - 3}{4r} \) when \( r = 3 \), we can substitute \( r = 3 \) into the expression.

1. Substitute \( r = 3 \):

\[ \frac{3^2 - 3}{4 \cdot 3} \]

2. Calculate \( 3^2 \):

\[ 3^2 = 9 \]

3. Substitute back into the expression:

\[ \frac{9 - 3}{4 \cdot 3} \]

4. Simplify \( 9 - 3 \):

\[ \frac{6}{4 \cdot 3} \]

5. Calculate \( 4 \cdot 3 \):

\[ 4 \cdot 3 = 12 \]

6. Substitute back into the expression:

\[ \frac{6}{12} \]

7. Simplify \( \frac{6}{12} \):

\[ \frac{1}{2} \]

Thus, the value of the expression when \( r = 3 \) is \(\frac{1}{2}\).