Question

If f(x) = x + 9, find the value of x if f(x) = 15.

Answer 1

This is really simple. It's saying that the value of x is 15. So the answer is simply 15 + 9 = 24.

Answer 2

NO!

Answer 3

?

Answer 4

That'd be f(15) not f(x) = 15

Answer 5

Whoops lol. Yeah just realized that.

Answer 6

\( \color{Black}{\Rightarrow f(x) = 15}\)
Substitute f(x) with x + 9

\( \color{Black}{\Rightarrow x + 9 = 15}\)

Answer 7

Now get it?

Answer 8

Oh. We're all brilliant. XD

Answer 9

My bad. Sry @ParthKohli

Answer 10

Nope.. it's all good =)

Answer 11

thanks you guys

Answer 12

You are welcome :)