To find the value of the expression \( 2x^2 - 11 \) when \( x = 3 \), you can substitute \( 3 \) for \( x \):
\[ 2(3^2) - 11 \]
First, calculate \( 3^2 \):
\[ 3^2 = 9 \]
Now substitute this value back into the expression:
\[ 2(9) - 11 \]
Next, multiply \( 2 \) by \( 9 \):
\[ 18 - 11 \]
Now, subtract \( 11 \) from \( 18 \):
\[ 18 - 11 = 7 \]
Therefore, the value of \( 2x^2 - 11 \) when \( x = 3 \) is \( 7 \).