Question

f(x)=4x+5
f(4)=

Question 9
I’m stuck on this help please!!

Answer 1

Answer:

$f(x) = 4x+5\\f(4)=4x+5\\f(4)=4(4)+5\\f(4)=16+5\\f(4)=21$

Step-by-step explanation:

The x in $f(x)$ is the number you plug into the x spot. think of f(x) like y.

$f(x) =y$ but it's y that tells you what x is supposed to be.

for example:

$y=mx+b\\f(x)=mx+b\\f(x)=4x+5\\f(3)=4(3)+5\\f(4)=4(4)+5\\f(5)=4(5)+5$

So you can say that f(any number) is a place holder for the y that tells you what x is supposed to be plugged in.