Evaluate the function f(x) =4x +1 at the given values of the independent variable and simplify.

a. f(-9)

b. f(x+5)

c. f(-x)

a. f(-9)= (Simplify your answer.)

b. f(x+5)= (Simplify your answer.)

c. f(-x)= (Simplify your answer.)

1 answer

To evaluate the function \( f(x) = 4x + 1 \) at the given values, let's solve each:

a. \( f(-9) \)

To find \( f(-9) \), substitute \(-9\) for \(x\):

\[ f(-9) = 4(-9) + 1 \] \[ = -36 + 1 \] \[ = -35 \]

So, \[ \text{a. } f(-9) = -35 \]

b. \( f(x+5) \)

To find \( f(x+5) \), substitute \(x + 5\) for \(x\):

\[ f(x+5) = 4(x+5) + 1 \] \[ = 4x + 20 + 1 \] \[ = 4x + 21 \]

So, \[ \text{b. } f(x+5) = 4x + 21 \]

c. \( f(-x) \)

To find \( f(-x) \), substitute \(-x\) for \(x\):

\[ f(-x) = 4(-x) + 1 \] \[ = -4x + 1 \]

So, \[ \text{c. } f(-x) = -4x + 1 \]

Summary of Results:

  • a. \( f(-9) = -35 \)
  • b. \( f(x+5) = 4x + 21 \)
  • c. \( f(-x) = -4x + 1 \)