Question

F(x) = 5x +8
Find f(7) -f(3)

Answer 1

Answer: 20

Explanation:

We can calculate this step by step. To compute f(7) - f(3), we will first figure out the value of f(7), then f(3), and then, we'll subtract the two.

So let's start. To find f(7), we substitute 7 into the function.

`\sf{f(x) = 5x + 8}` {Given function}

`\sf{f(7) = 5(7) + 8}` {Substitute 7 everywhere x is}

`\sf{f(7) = 35 + 8}` {Add}

`\sf{f(7) = 43}` {Result}

`\dotfill`

The next step is to find f(3). This can be solved the same way.

`\sf{f(x)=5x+8}` {Given function}

`\sf{f(3)=5(3)+8}` {Simplify}

`\sf{f(3)=15+8}` {Add}

`\sf{f(3)=23}` {Result}

Now, we just subtract:

`\sf{43-23}` {Subtract}

`\sf{20}` {Result}

`\large\bigstar\quad\underline{\boxed{\sf{f(7)-f(3)=20}}}`

Answer 2

Explanation:

We know

Function Rule: f(x) = 5x + 8

a. Find f(7) - f(3)

First, let's find f(7):

f(7) = 5(7) + 8

f(7) = 35 + 8

f(7) = 43

Now, let's find f(3):

f(3) = 5(3) + 8

f(3) = 15 + 8

f(3) = 23

Now we calculate

f(7) - f(3) = 43 - 23 = 20