Answer :
To evaluate the function [tex]f(x) = 7x - 8[/tex] at the given values, we need to substitute the values of [tex]x[/tex] into the function and simplify.
Let's solve for each part:
a. Evaluate [tex]f(9)[/tex]:
- Substitute [tex]x = 9[/tex] into the function: \[tex]f(9) = 7 \times 9 - 8 \\[/tex]
- Calculate [tex]7 \times 9 = 63[/tex]
- Subtract 8 from 63: \[tex]63 - 8 = 55 \\[/tex]
Thus, [tex]f(9) = 55[/tex].
b. Evaluate [tex]f(4)[/tex]:
- Substitute [tex]x = 4[/tex] into the function: \[tex]f(4) = 7 \times 4 - 8 \\[/tex]
- Calculate [tex]7 \times 4 = 28[/tex]
- Subtract 8 from 28: \[tex]28 - 8 = 20 \\[/tex]
Thus, [tex]f(4) = 20[/tex].
Therefore, the values of the function are [tex]f(9) = 55[/tex] and [tex]f(4) = 20[/tex].
The correct option is:
- 55, 20
