Question

Find each function value1. f(7) if (x)=5x2. f(4) if f(x)=3x-1

Answer 1

ANSWER

$1. \: \: f(7) = 35$

$2. \: f(4) = 11$

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

$f(x) = 5x$

To find f(7), we substitute x=7, into the function.

$\implies f(7) =5(7) = 5 \times 7 = 35$

The second function is

$f(x) = 3x - 1$

To find f(4), we replace x with 4 to obtain,

$f(4) = 3(4) - 1$

$f(4) = 12 - 1 = 11$