It's pretty pathetic when I can't even do substitution for equations and everyone says I am the smart kid!! :(. Help? It's pretty pathetic when I can't even do substitution for equations and everyone says I am the smart kid!! :(. Help? @Mathematics
yes... (x+y+z=2) (x+2z=5) (2x+y-z=-1)
thats ok, i cant do diffy qs to well and im a veritable genius lol
we can see that x = 5-2z from the 2nd eq
sub that into the others
all a system of equations is is saying that there are common values for the variables
as such, we can substitute "quasi" values and come up with solid values
since x has to equal 5-2z; we can simply use that in the other equations to simplify matters
uhmm well i dont know what quasi is lol
quasi means .... youre gonna make me look up my own words aintcha
having the appearance of, resembling, related to in some fashion that is not concretely established
haha i guess so. :)
x+y+z=2 x+2z=5 <-- x = 5-2z 2x+y-z=-1 ......................................... substitute it in (5-2z)+y+z=2 x = 5-2z 2(5-2z)+y-z=-1 ........................................ "solve" 5-2z+y+z=2 5-z+y = 2 x = 5-2z 2(5-2z)+y-z=-1 10-4z+y-z = -1 5z+y = -11 etc
the 2 new eqs that result can be compared for either z or y now 5-z+y = 2 -z+y = -3 y = z-3 ................................. substitute this "value" since its got to hold for all ys 5z+y = -11 5z+(z-3) = -11 5z+z-3 = -11 6z = -8 z = -4/3 if im right
okay this is what i have
and since y = z-3, and z=-4/3 y = -4/3 -3 y = -13/3 i hate fractions they always make me worry
and of course we had: x = 5-2z, and z=-4/3 x = 5-2(-4/3) = 5+ 8/3 = 23/3 maybe
(x+y+z=2) (x+2z=5) (2x+y-z=-1) x=-2z+5 -2z+5+y+z=2 -z+y=-3 y=z-3 2(-2z+5)+z-3-z=-1 -4z+10+z-3-z=-1 am i doing any of this right?
i messed it up someplace since the wolf disagrees with me ;) http://www.wolframalpha.com/input/?i=%28x%2By%2Bz%3D2%29+and++%28x%2B2z%3D5%29+and+%282x%2By-z%3D-1%29
that looks good
from what i can parse from it
okay then i might have this...but i might still be coming back for more help. :)
right here is my mess: 2(5-2z)+y-z=-1 10-4z+y-z = -1 5z+y = -11 <-- should be -5, i dropped me sign :/
okay i figured it out lol. Thanks for the help. :).
You will probably be getting a lot of medals from me btw lol.
i already got lots of medals ;) but thnx anyhoos
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