Question

If `f(x) = 3x^2-x`, what is `f(-5)`?

Answer 1

`80`

Explanation:

`f(-5)` means that `x=-5`. With this in mind, we can plug this into `f(x)`. We will get

`f(-5)=3(-5)^2-(-5)`

This simplifies to

`3(25)+5=80`

Hope this helps!

Answer 2

`80`

Explanation:

`"substitute " x = -5 " into "f(x)`

`f(color(red)(-5))=3(color(red)(-5))^2-(color(red)(-5))`

`color(white)(xxxx)=(3xx25)+5`

`color(white)(xxxx)=75+5=80`