Help with math assignment

I don't understand the third question mainly, but it all seems quite confusing :/

If f(x) = 3x - 2 determine each of the following;

1) f(3)
2) f(-2)
3) f(2c)
4) 3f(-4)

I think I understand the first two,
1) =7
2) =-8

But I may be wrong :/
Please help :(

You are right on the first two.

The answer to number 3) is "6c - 2" .

The answer to number 4) is "-14"

For number 3, simply insert "2c" anywhere were you see x.

f(2c) = 3(2c) - 2 = 6c - 2.

You were probably confused by the letter "c", which represents any fixed constant in general. It doesn't really work much differently than if you were to have a specific number in there.

Hope I helped.

When you have your function of x, whatever is inside your parentheses gets plugged in for X, like you did for the first two.

So, for the third one, plug in 2c wherever you see an X in your function, making it 3(2c)-2, which equals 6c-2. For the fourth one, you plug in -4 for X like you normally would, but then you multiply the entire thing by 3, making it 3[3(-4)-2]

Hope that helps.