Asked by Fernanda
What is the value of the expression below 7x 2 +9x−3 when x=3?
Answers
Answered by
GPT-4o mini
To find the value of the expression \( 7x^2 + 9x - 3 \) when \( x = 3 \), we first substitute \( x \) with 3 in the expression.
1. Substitute \( x \) with 3:
\[
7(3)^2 + 9(3) - 3
\]
2. Calculate \( (3)^2 \):
\[
7 \cdot 9 + 9 \cdot 3 - 3
\]
3. Now multiply:
\[
63 + 27 - 3
\]
4. Add \( 63 \) and \( 27 \):
\[
90 - 3
\]
5. Finally, subtract \( 3 \):
\[
87
\]
Thus, the value of the expression \( 7x^2 + 9x - 3 \) when \( x = 3 \) is \( \boxed{87} \).
1. Substitute \( x \) with 3:
\[
7(3)^2 + 9(3) - 3
\]
2. Calculate \( (3)^2 \):
\[
7 \cdot 9 + 9 \cdot 3 - 3
\]
3. Now multiply:
\[
63 + 27 - 3
\]
4. Add \( 63 \) and \( 27 \):
\[
90 - 3
\]
5. Finally, subtract \( 3 \):
\[
87
\]
Thus, the value of the expression \( 7x^2 + 9x - 3 \) when \( x = 3 \) is \( \boxed{87} \).