Question

In the following exercises, evaluate the function

$$\begin{gathered} a.f\left(2\right) \\ b.f(-1) \\ c.f\left(a\right) \end{gathered}$$

Function:$f\left(x\right)=5x-3$

Short answer

a. The value of the function, $f\left(x\right)=5x-3$at $x=2$is$7$.

b. The value of the function, $f\left(x\right)=5x-3$at $x=-1$is $-8$.

c. The value of the function,$f\left(x\right)=5x-3$at $x=a$is$5a-3$.

Step-by-step solution

Step 1. Given Information

The given function is$f\left(x\right)=5x-3$.

Part (a). Step 1. Evaluating the value of the function at x=2.

To evaluate $f\left(2\right)$, substitute $2$for $x.$

$$\begin{gathered} f\left(2\right)=5\left(2\right)-3 \\ f\left(2\right)=10-3 \\ f\left(2\right)=7 \end{gathered}$$

Therefore,$f\left(2\right)=7.$

Part (b) Step 1. Evaluating the function at x=-1. 

To evaluate $f(-1),$substitute $-1$for $x.$

$$\begin{gathered} f(-1)=5(-1)-3 \\ f(-1)=-5-3 \\ f(-1)=-8 \end{gathered}$$

Therefore, $f(-1)=-8$.

Part (c) Step 1. Evaluating the function at x=a.

To evaluate $f\left(a\right),$substitute $a$for$x$.

$$\begin{gathered} f\left(a\right)=5\left(a\right)-3 \\ f\left(a\right)=5a-3 \end{gathered}$$

Therefore,$f\left(a\right)=5a-3.$