# Working out total cost

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• Oct 9th 2007, 07:33 PM
JTE
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 :D 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 :D

http://img116.imageshack.us/img116/1...gggggggzq6.png

Thanks very much
• Oct 9th 2007, 07:47 PM
JTE
With C being Cost...
• Oct 9th 2007, 08:18 PM
Jhevon
Quote:

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 :D 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 :D

http://img116.imageshack.us/img116/1...gggggggzq6.png

Thanks very much

just work it out piece by piece.

$3^3 = 27$

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

$40(3) = 120$

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