Algebra

[Neil]

Dilbert, I made a C++ program to work out the answer for the question you posted in quotes. I assume you have to find the right X and Y values that make the "X" on the left hand side (that I assume is a different X, otherwise it makes little sense) a maximum or minimum value. The maximum value is 27 when Y = 9 and X = 0 and the minimum value is 0 when both equal zero. Although it's fairly easy to solve just by looking at it. Try posting a more difficult equation to solve, so I can prove once and for all that itteratertive something methods rule the world, MuWaHaHaHa

[Dilbert]

Very well, Neil. The following is the type of problem found a homework assignment that we covered a few days ago:

Solve the linear system by finding X, Y, and Z

x - 2y + 3z = 7
2x + y + z = 4
-3x + 2y - z = -10

Here's the page on how to solve it: http://tutorial.math.lamar.edu/AllBrowsers/1314/SystemsThreeVrble.asp

[Neil]

OK, but not now. It's 3AM

[Neil]

Don't worry I haven't forgotten... just lots of work...

[unlovedwarrior]

i just read this thread and ill work the problem out by hand and we can compare. plus i need to refresh my math

[steelegbr]

My results were:

x = 9/4
y = -5/4
z = 3/4

How come they look so simple yet give such silly answers!

[unlovedwarrior]

did you graph it??

[steelegbr]

did you graph it??

No. The only 3D maths work I've done is vectors.

It's supposed to be taken down from a 3x3 system to a 2x2 and then again down to a 1x1.

If you do it properly, most of the time it will come out as fractions.

There are also times when there is no solution (E.g. 2 of the 3 equations are the same).