Question

Find the value of the function y=3x2−21
when x=4
.(1 point)
y=

Answer 1

To find the value of the function \( y = 3x^2 - 21 \) when \( x = 4 \), we substitute \( 4 \) for \( x \):

\[
y = 3(4)^2 - 21
\]

Calculating \( (4)^2 \):

\[
(4)^2 = 16
\]

Now substituting it back into the equation:

\[
y = 3 \times 16 - 21
\]

Calculating \( 3 \times 16 \):

\[
3 \times 16 = 48
\]

Now we subtract 21 from 48:

\[
y = 48 - 21 = 27
\]

Thus, the value of the function when \( x = 4 \) is:

\[
\boxed{27}
\]