ANSWER
[tex]1. \: \: f(7) = 35[/tex]
[tex]2. \: f(4) = 11[/tex]
EXPLANATION
To find the value of a function, f(x) at a given value x=a, we plug in x=a into f(x) to obtain f(a) in simplified form.
The first function is
[tex]f(x) = 5x[/tex]
To find f(7), we substitute x=7, into the function.
[tex] \implies f(7) =5(7) = 5 \times 7 = 35[/tex]
The second function is
[tex]f(x) = 3x - 1[/tex]
To find f(4), we replace x with 4 to obtain,
[tex]f(4) = 3(4) - 1[/tex]
[tex]f(4) = 12 - 1 = 11[/tex]
