Question

If f(x) = 9 – 4|x + 1|, find f(–5).

(Points : 1)
–15
–7
7
23

Answer 1

\(\large\color{black}{ \displaystyle f(x) = 9 - 4\left|x + 1\right| }\)

To find f(-5), plug in -5 for x.

Answer 2

\(\large\color{black}{ \displaystyle f(\color{red}{-5}) = 9 - 4\left|\color{red}{-5} + 1\right| }\) this is how you plug it in.

Now, you only need to simplify the right side, but remember that absolute value (of any number) is always positive.

Answer 3

1 for -5 + 1

Answer 4

then we would have f(-5) = 9 - 4 /1/

Answer 5

what would i do next?

Answer 6

\(\large\color{slate}{\displaystyle f(-5) = 9 - 4|-5+1|}\)
\(\large\color{slate}{\displaystyle f(-5) = 9 - 4|-4|}\)
\(\large\color{slate}{\displaystyle f(-5) = 9 - 4(4)}\)

Answer 7

see how it is?

Answer 8

so then it would be 4 times 4 right? That would equal 16. so we would have 9-16 left?

Answer 9

and that would equal -7. So would the answure be B, -7?

Answer 10

yes, -7 is correct.

Answer 11

Thank you!