When the input is 4, the output of f(x) = x + 21 is

Step-by-step explanation:

When the input is 4, the output of f(x) = x + 21 is f(4).

Substitute x = 4 to f(x):

f(4) = 4 + 21 = 25

25

Step-by-step explanation:

We can find the output by plugging in 4 as x into the function:

f(x) = x + 21

f(4) = 4 + 21

f(4) = 25

step-by-step explanation:

graph using a few selected

x         y

-1       15

0         6

1         2.4

2       0.96