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ambeeeerlw
Group Title
I don't understand the x and y determinant. will someone explain it with an example? I'm needing solve some like this:
x + y = 12
x  y = 10
What is the value of the xdeterminant for the system shown?
 5 months ago
 5 months ago
ambeeeerlw Group Title
I don't understand the x and y determinant. will someone explain it with an example? I'm needing solve some like this: x + y = 12 x  y = 10 What is the value of the xdeterminant for the system shown?
 5 months ago
 5 months ago

This Question is Open

HourglassMage Group TitleBest ResponseYou've already chosen the best response.0
add both equations
 5 months ago

HourglassMage Group TitleBest ResponseYou've already chosen the best response.0
you'll get 2x = 22
 5 months ago

HourglassMage Group TitleBest ResponseYou've already chosen the best response.0
solve for that, and you'll get 11
 5 months ago

ambeeeerlw Group TitleBest ResponseYou've already chosen the best response.0
I though that too, but that's not an answer. :(
 5 months ago

ambeeeerlw Group TitleBest ResponseYou've already chosen the best response.0
thought*
 5 months ago

HourglassMage Group TitleBest ResponseYou've already chosen the best response.0
what are the options?
 5 months ago

ambeeeerlw Group TitleBest ResponseYou've already chosen the best response.0
22 12 2
 5 months ago

HourglassMage Group TitleBest ResponseYou've already chosen the best response.0
I have to go, I'll respond to this in a little bit. Sorry.
 5 months ago

tkhunny Group TitleBest ResponseYou've already chosen the best response.0
x + y = 12 x  y = 10 D = (1)(1)(1)(1) Dx = (12)(1)(10)(1) Dy = (1)(10)(1)(12)
 5 months ago

ambeeeerlw Group TitleBest ResponseYou've already chosen the best response.0
That's fine. Thanks though :)
 5 months ago

ambeeeerlw Group TitleBest ResponseYou've already chosen the best response.0
Are you saying it's 22? It's asking for the x determinant if you're wondering. I just want to be able to solve the future ones. :)
 5 months ago

mathmale Group TitleBest ResponseYou've already chosen the best response.2
@ambeeeerlw : Determinants are not used much any longer. However, you're apparently expected to know how to apply determinants to solving systems of linear equations. Have you tried looking up "determinants" on the 'Net? If you want to learn how do use determinants, either @tkhunny or I would be happy to help you ... but we do not give out just answers.
 5 months ago

ambeeeerlw Group TitleBest ResponseYou've already chosen the best response.0
I actually wasn't expecting just answers, I was double checking his work so I'd know how to future problems. I'm not trying to just collect answers, I swear. I have looked it up, but I can;t a way that explains it well enough where I fully understand. :( Can you help me?
 5 months ago

ambeeeerlw Group TitleBest ResponseYou've already chosen the best response.0
( or her work, I didn't see who it was)
 5 months ago

tkhunny Group TitleBest ResponseYou've already chosen the best response.0
"Cramer's Rule" is very interesting. It just works. It leans toward what we like to call an "Existence" result. This means it may or may not be very useful in the real world, but it demonstrates that (or under what conditions) the solution exists. Good thing to know.
 5 months ago

ambeeeerlw Group TitleBest ResponseYou've already chosen the best response.0
My teacher didn't even mention it is "Cramer's Rule," so that's a nice factor to know.. I do online school, and I can't really get it touch with my teacher, reasoning behind me getting help from her.
 5 months ago

mathmale Group TitleBest ResponseYou've already chosen the best response.2
@tkhunny typed this out for you earlier: x + y = 12 x  y = 10 D = (1)(1)(1)(1) Dx = (12)(1)(10)(1) Dy = (1)(10)(1)(12) First, he found the "system determinant." He realized that x + y = 12 x  y = 10 can be rewritten as 1x+1y=12 1x1y=10 which we need to do because we need those coefficients of x and y. Notice how the coefficients (alone) are 1 1 1 1 tkhunny now finds the "system determinant."dw:1396529907980:dw
 5 months ago

mathmale Group TitleBest ResponseYou've already chosen the best response.2
The result is 1 1, or 2. The system determinant is 2. Note that this is exactly the result obtained by tkhunny earlier. Have you seen this kind of work done before?
 5 months ago

ambeeeerlw Group TitleBest ResponseYou've already chosen the best response.0
Yes, that is the only one have and that I understand.
 5 months ago

mathmale Group TitleBest ResponseYou've already chosen the best response.2
Good. Now we need to find x. We take the system determinant, toss out the first column, and replace it with the constants (12 and 10):dw:1396530274277:dw
 5 months ago

ambeeeerlw Group TitleBest ResponseYou've already chosen the best response.0
the products of those would be 12 and 10, right?
 5 months ago

mathmale Group TitleBest ResponseYou've already chosen the best response.2
Right, and that adds up to 22. Thus, your x is found in this manner:dw:1396530623039:dw
 5 months ago

mathmale Group TitleBest ResponseYou've already chosen the best response.2
close. Try again.
 5 months ago

mathmale Group TitleBest ResponseYou've already chosen the best response.2
and your y value is
 5 months ago

ambeeeerlw Group TitleBest ResponseYou've already chosen the best response.0
I meant 11, oops :p
 5 months ago

ambeeeerlw Group TitleBest ResponseYou've already chosen the best response.0
y value is 1? I think
 5 months ago

mathmale Group TitleBest ResponseYou've already chosen the best response.2
dw:1396530712310:dw
 5 months ago

mathmale Group TitleBest ResponseYou've already chosen the best response.2
Cool. Yes, y=1. Solution is (11,1). congrats!
 5 months ago

ambeeeerlw Group TitleBest ResponseYou've already chosen the best response.0
I don't understand because the answers are only 22,12, and 2. This is what confuses me
 5 months ago

ambeeeerlw Group TitleBest ResponseYou've already chosen the best response.0
Is it asking for another part of the question? I'm unsure.
 5 months ago

mathmale Group TitleBest ResponseYou've already chosen the best response.2
@tkhunny's "answers" are intermediate results. He gave you D=2, Dx = 22 and Dy = 2.dw:1396531164233:dw
 5 months ago

ambeeeerlw Group TitleBest ResponseYou've already chosen the best response.0
Oh, I apologize. So, basically the Dy and Dx are supported off of the system determinate?
 5 months ago

mathmale Group TitleBest ResponseYou've already chosen the best response.2
that's right!! they are both modifications of the system determinant.
 5 months ago

mathmale Group TitleBest ResponseYou've already chosen the best response.2
And nothing to apologize for! I so much appreciate your sticking with this until completion. Hope to get to work with you again.
 5 months ago

ambeeeerlw Group TitleBest ResponseYou've already chosen the best response.0
Okay!!! That helps tremendously!! Thank you sososo much!!! I now understand :D
 5 months ago

mathmale Group TitleBest ResponseYou've already chosen the best response.2
That's like music to the ears! :)
 5 months ago
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