Evaluate the function \( f(x)=7 x+9 \) at the given values of the independent variable and simplify. \( \begin{array}{lll}\text { a. } f(6) & \text { b. } f(x+2) & \text { c. } f(-x)\end{array} \) a. \( f(6)=\square \) (Simplify your answer.)

To evaluate the function \( f(x) = 7x + 9 \): a. For \( f(6) \): \[ f(6) = 7(6) + 9 = 42 + 9 = 51. \] So, \( f(6) = 51 \). b. For \( f(x+2) \): \[ f(x+2) = 7(x + 2) + 9 = 7x + 14 + 9 = 7x + 23. \] So, \( f(x + 2) = 7x + 23 \). c. For \( f(-x) \): \[ f(-x) = 7(-x) + 9 = -7x + 9. \] So, \( f(-x) = -7x + 9 \). In summary: a. \( f(6) = 51 \) b. \( f(x+2) = 7x + 23 \) c. \( f(-x) = -7x + 9 \)