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octoberchick1011
Group Title
Solve the system using an augmented matrix. Please show all your steps! Thanks! (:
x 3y = 17
2x 6y = 26
 2 years ago
 2 years ago
octoberchick1011 Group Title
Solve the system using an augmented matrix. Please show all your steps! Thanks! (: x 3y = 17 2x 6y = 26
 2 years ago
 2 years ago

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amistre64 Group TitleBest ResponseYou've already chosen the best response.0
can you set up the matrix?
 2 years ago

octoberchick1011 Group TitleBest ResponseYou've already chosen the best response.0
Yes: 1 3  17 2 6  26
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
Your next step is to make the upper left corner equal to 1. How do we do this?
 2 years ago

octoberchick1011 Group TitleBest ResponseYou've already chosen the best response.0
Umm.. I'm not entirely sure  I'm not very good at these types of problems. I think we would multiply by 3 right...?
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
What do we multiply 1 by to get 1 ?
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
1 times ??? = 1
 2 years ago

octoberchick1011 Group TitleBest ResponseYou've already chosen the best response.0
1.
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
so do this across the entire first row....ie multiply EVERY number in row 1 by 1
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
1 3  17 2 6  26 1 3  17 1*R1 2 6  26
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
The notation 1*R1 means "1 times Row 1"
 2 years ago

octoberchick1011 Group TitleBest ResponseYou've already chosen the best response.0
Okay so it would be: 1 3  17 right?
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
yes it would be
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
The upper left corner is a 1. This is known as the pivot (for the first column). Everything thing else must be a zero in order to obtain the solutions for x and y. So how to we turn that 2 (below the pivot of 1) into a 0 ?
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
oh sry, i made a typo the second row should be 2 6  26 instead of 2 6  26
 2 years ago

octoberchick1011 Group TitleBest ResponseYou've already chosen the best response.0
You would make the 2 a zero my by multiplying it by 0..? I think..
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
well if you did that, everything in row 2 would become 0
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
then you'd get 0x + 0y = 0...which is completely useless now
 2 years ago

octoberchick1011 Group TitleBest ResponseYou've already chosen the best response.0
Oh. That's true..
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
Instead, you can add/subtract multiples of row 1 to row 2
 2 years ago

octoberchick1011 Group TitleBest ResponseYou've already chosen the best response.0
So does that mean we would subtract 2 from row 2?
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
Notice in the first column we have 1 2
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
If we subtract row 1 from row 2, we get 2  1 = 1 But that's not zero However, if we subtract row 1 (twice) from row 2, we get 2  1  1 = 0
 2 years ago

octoberchick1011 Group TitleBest ResponseYou've already chosen the best response.0
Okay. So does that mean that row 2 looks like this now: 0 6  26
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
not quite
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
6  2*(3) = 12 so the 2nd element in row 2 is 12
 2 years ago

octoberchick1011 Group TitleBest ResponseYou've already chosen the best response.0
Ugh, I'm so confused  lol, these kinds of probles frustrate me! :P
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
26  2*17 = 60
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
so the 3rd element in row 2 is 60
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
after this, you should have 1 3  17 0 12  60
 2 years ago

jim_thompson5910 Group TitleBest ResponseYou've already chosen the best response.0
what's next?
 2 years ago
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