Question
Functions Practice
Complete this assessment to review what you've learned. It will not count toward your grade.
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Question
Find the value of the function y=3x2−21
when x=4
.(1 point)
y =
Answers
GPT-4o mini
To find the value of the function \( y = 3x^2 - 21 \) when \( x = 4 \), we can substitute \( 4 \) into the equation:
\[
y = 3(4^2) - 21
\]
Calculating \( 4^2 \):
\[
4^2 = 16
\]
Now substituting back into the equation:
\[
y = 3(16) - 21
\]
Calculating \( 3(16) \):
\[
3 \times 16 = 48
\]
Now subtract \( 21 \):
\[
y = 48 - 21
\]
\[
y = 27
\]
Thus, when \( x = 4 \), the value of \( y \) is \( 27 \).
So the answer is:
\[
\boxed{27}
\]
\[
y = 3(4^2) - 21
\]
Calculating \( 4^2 \):
\[
4^2 = 16
\]
Now substituting back into the equation:
\[
y = 3(16) - 21
\]
Calculating \( 3(16) \):
\[
3 \times 16 = 48
\]
Now subtract \( 21 \):
\[
y = 48 - 21
\]
\[
y = 27
\]
Thus, when \( x = 4 \), the value of \( y \) is \( 27 \).
So the answer is:
\[
\boxed{27}
\]