Q2. - Algebra 2

Question

2. Find the value of $\mathbf{f}\left(\mathbf{15}\right)$ if $\mathbf{f}\left(\mathbf{x}\right)=\mathbf{100}\mathbf{x}-\mathbf{5}{\mathbf{x}}^{\mathbf{2}}$. (Lesson 2-1)

Step-by-Step Solution

Answer

The value of $f\left(15\right)$ is 375.

Step 1 – State the concept

The value of $f\left(a\right)$ can be obtained by substituting a for each $x$ in the expression for $f\left(x\right)$.

Step 2 – List the given data

The function $f\left(x\right)=100x-5x^2$. The objective is to find $f\left(15\right)$.

Step 3 – Evaluate the required value

Put $x=15$ in $f\left(x\right)=100x-5x^2$ to get,

 $\begin{array}{c}f\left(15\right)=100\left(15\right)-5{\left(15\right)}^2\\ =1500-5\left(225\right)\\ =1500-1125\\ =375\end{array}$

So, $f\left(15\right)=375$.

Thus, the value of $f\left(15\right)$ is 375.