Question

if f(x) = 2x² + 3x - 1, what is f(2)? what is the area of a circle with radius 5 units? (use π ≈ 3.14)

Explanation:

Step1: Substitute x = 2 into f(x)

$f(2)=2\times2^{2}+3\times2 - 1$

Step2: Calculate powers first

$2\times2^{2}=2\times4 = 8$

Step3: Calculate multiplications

$3\times2=6$

Step4: Perform addition and subtraction

$f(2)=8 + 6-1=13$

Step5: Calculate area of circle

The formula for the area of a circle is $A=\pi r^{2}$. Given $r = 5$, then $A=\pi\times5^{2}=25\pi$. Using $\pi\approx3.14$, $A = 25\times3.14=78.5$ but in terms of $\pi$ the area is $25\pi$.

Answer:

1. A. 13
2. A. $25\pi$