Question

For the function f(x) = 2x^2 - 5x + 9, find f(-3) I got 42 by pluging in -3 for x is that right?

Answer 1

\(\large\color{slate}{ f(x) = 2x^2 - 5x + 9 }\)
\(\large\color{slate}{ f(-3) = 2(-3)^2 - 5(-3) + 9 }\)
\(\large\color{slate}{ f(-3) = 2(9) +15 + 9 }\)
\(\large\color{slate}{ f(-3) = 18 +24 }\)
\(\large\color{slate}{ f(-3) = 42 }\)

yes!

Answer 2

well done (I just checked it)

Answer 3

Thanks : ) sometimes I think I have to factor it or something which throws me off.

Answer 4

yes, you just needed to plug it in, which you did successfully.
(no factoring)