# Thread: Working out total cost

1. ## Working out total cost

If someone could give me the breakdown of how you get the final answer in this equation I will love you forever Just need to know how you get 57 so I can apply the same theory to other problems!

I have done it on paint because I haven't got a clue how to write cubed and squared on a keyboard

Thanks very much

2. With C being Cost...

3. Originally Posted by JTE
If someone could give me the breakdown of how you get the final answer in this equation I will love you forever Just need to know how you get 57 so I can apply the same theory to other problems!

I have done it on paint because I haven't got a clue how to write cubed and squared on a keyboard

Thanks very much
just work it out piece by piece.

$3^3 = 27$

$10(3)^2 = 10(9) = 90$

$40(3) = 120$

thus, $c(3) = 3^3 - 10(3)^2 + 40(3) = 27 - 90 + 120 = 57$