How do you find f(-3) given 3-5x if x ≤0, 4x if 0<x<8, 5x+3 if x ≥ 8?

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Answer 1 · 2017-07-05T20:02:27

See a solution process below:

Because: $- 3 \leq 0$ $-3 <= 0$ we will use the function $f (x) = 3 - 5 x$ $f(x) = 3 - 5x$

to solve this problem.

To find $f (- 3)$ $f(-3)$ we will substitute $- 3$ $color(red)(-3)$ for each occurrence of $x$ $color(red)(x)$ in $f (x) = 3 - 5 x$ $f(x) = 3 - 5x$

$f (x) = 3 - 5 x$ $f(color(red)(x)) = 3 - 5color(red)(x)$ becomes:

$f (- 3) = 3 - (5 \cdot - 3)$ $f(color(red)(-3)) = 3 - (5 * color(red)(-3))$

$f (- 3) = 3 - (- 15)$ $f(color(red)(-3)) = 3 - (-15)$

$f (- 3) = 3 + 15$ $f(color(red)(-3)) = 3 + 15$

$f (- 3) = 18$ $f(color(red)(-3)) = 18$