Question

b) evaluate each function

1. $f(x) = 8x - 9$ ; find $f(-3)$
2. $f(x) = 4x$ ; find $f(-15)$

c) if $f(x) = 3(-2x + 7)$ ; find the following

1. $f(-7) = $
2. $f(13) = $
3. $f(11) = $
4. $f(-8) = $

d) if $f(x) = -x - 11$ ; find the following.

1. $4f(-2) + 5f(1) = $
2. $3f(5) \times f(2) = $
3. $-5f(12) - 2f(-9) = $
4. $\frac{f(9)}{f(-6)} = $

e) what is the value of $f(4)$, if $f(x) = -4(x + 3) - 14$?
a) 62
b) -24
c) -42
d) 8

Explanation:

B) Evaluate each function

1) \( f(x) = 8x - 9 \), find \( f(-3) \)

Step1: Substitute \( x = -3 \) into \( f(x) \)

\( f(-3) = 8\times(-3) - 9 \)

Step2: Calculate the multiplication and subtraction

\( 8\times(-3) = -24 \), then \( -24 - 9 = -33 \)

Step1: Substitute \( x = -15 \) into \( f(x) \)

\( f(-15) = 4\times(-15) \)

Step2: Calculate the multiplication

\( 4\times(-15) = -60 \)

Step1: Substitute \( x = -7 \) into \( f(x) \)

\( f(-7) = 3(-2\times(-7) + 7) \)

Step2: Calculate inside the parentheses

\( -2\times(-7) = 14 \), then \( 14 + 7 = 21 \)

Step3: Multiply by 3

\( 3\times21 = 63 \)

Answer:

\( -33 \)

2) \( f(x) = 4x \), find \( f(-15) \)