Anyone good at algebra?

[jesseweaver]

any help would be really appreciated. i just missed mon and tues for hunting and my algebra 2 teacher said if i figure this out, she'll give me 25 extra credit points and i need it, but i wasnt here when we did some of this stuff.

4w+x+2y-3z=-16
-3w+3x-y+4z=20
-w+2x+5y+z=-4
5w+4x+3y-z=-10

[79400ex]

What are you trying to due here.? More Info please.

[tgreenz400]

Originally posted by 79400ex
What are you trying to due here.? More Info please. you find the value of the letters

Example: A=4 B=8 C=7

[parkers30]

I'm going to assume he needs to solve the system of equations... pretty basic but very time consuming
1st you need to solve one equation for one unknown say X in the first equation....
x=3z-4w-2y-16

then substitute that into another equation. this is the second with the above inserted in place of x...

-3w+3(3z-4w-2y-16)-y+4z=20

and then solve that equation for one of unknowns still left and move down the list of equations until you are left with unknown and constants.

I don't really want to do all of it for you

[atvrider23054]

W = -1
X = 1
Y = -2
Z = 3

[parkers30]

glory of the Ti-89 is that it does all of that for you... I just figured he probably needed to show work for extra credit

[416exfreak]

Originally posted by parkers30
I just figured he probably needed to show work

My teacher will throw your work away if you just give her awnsers. It pisses me off, because alot of it can be done in your head or in the calculator, and im a lazy person...I dont like writing it out.:p

[atvrider23054]

yea, but doing the work is soooo long. Just use the calculator, that alone, if you werent tought(sp?) how to, would impress the teacher.

[Robin Hood]

Just got done doing this on an exam.

Solve for one variable each and plug them into each other until you get x=_, y=_ etc.

Just looked at the prob. x is alone on the first, solve for that, y is alone on the second, etc.

Then just plug and chug. :D

[jesseweaver]

yea we gotta show work, its stupid. im starting it now, were not aloud to use calculators either. oh yea 8 replies already, kinda surprised me. thanks a lot.

[wilkin250r]

There are dozens of methods for solving linear equations. The first that people learn are most often the Substitution Method and Elimination Method.

Beyond that, there are several different methods when the equations are written in Matrix form, like the Inverse Method, Row-Echelon Method, and many other.


Did you teacher ever tell you which method you are supposed to use? I would assume it's the Substitution Method, that parkers30 explained above.

[pro-rider46]

if you have the same books we do. check out the back, they have the answers to the odd numbered problems. that mean only have of the work

[kawiefan]

Originally posted by pro-rider46
if you have the same books we do. check out the back, they have the answers to the odd numbered problems. that mean only have of the work
i always used to do that till we got our new math teacher he only gives us evens..... what a dik

[chris46250r]

I was as good in Algebra as the girl that sit in front of me. If you catch my drift. :D

[parkers30]

Originally posted by wilkin250r
There are dozens of methods for solving linear equations. The first that people learn are most often the Substitution Method and Elimination Method.

Beyond that, there are several different methods when the equations are written in Matrix form, like the Inverse Method, Row-Echelon Method, and many other.


Did you teacher ever tell you which method you are supposed to use? I would assume it's the Substitution Method, that parkers30 explained above.

I was going on the assumption that he was to use that method, thats all I learned until I got to college, the matrix based methods are much faster, but much harder to understand.