Question

What is the value of f(16) − f(0) when f(x) = 4x – 8?

Answer 1

Find f(16) by replacing 16 for x in 4x - 8
Then do the same for 0.
Then subtract the results.

Answer 2

so it would be 56-8
which gives you the answer of 48

Answer 3

@mathstudent55

Answer 4

You are on the right track, but you need to be careful.

\(f(x) = 4x - 8\)

\(f(16) = 4(16) - 8 = 64 - 8 = 56\)

\(f(0) = 4(0) - 8 = ~~?\)

Then
\(f(16) - f(0) = 56 - ~~? = ~~ ?\)

Answer 5

Look above.
What is f(0) equal to?

Answer 6

0

Answer 7

No.
f(0) = 4(0) - 8 = 0 - 8
What is 0 - 8 equal to?

Answer 8

oh sorry its equal to -8

Answer 9

Right.
Now remember you are subtracting the values of the function, so what is
56 - (-8) = ?

Answer 10

64

Answer 11

Correct.

Answer 12

That's what I meant by being careful.
You needed to do 56 - (-8) = 56 + 8 = 64, which you did now,
not 56 - 8 = 48, which you did earlier.

Answer 13

oh got it thank you so much

Answer 14

You're welcome.