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

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amistre64Best ResponseYou've already chosen the best response.0
can you set up the matrix?
 one year ago

octoberchick1011Best ResponseYou've already chosen the best response.0
Yes: 1 3  17 2 6  26
 one year ago

jim_thompson5910Best 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?
 one year ago

octoberchick1011Best 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...?
 one year ago

jim_thompson5910Best ResponseYou've already chosen the best response.0
What do we multiply 1 by to get 1 ?
 one year ago

jim_thompson5910Best ResponseYou've already chosen the best response.0
1 times ??? = 1
 one year ago

jim_thompson5910Best 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
 one year ago

jim_thompson5910Best ResponseYou've already chosen the best response.0
1 3  17 2 6  26 1 3  17 1*R1 2 6  26
 one year ago

jim_thompson5910Best ResponseYou've already chosen the best response.0
The notation 1*R1 means "1 times Row 1"
 one year ago

octoberchick1011Best ResponseYou've already chosen the best response.0
Okay so it would be: 1 3  17 right?
 one year ago

jim_thompson5910Best ResponseYou've already chosen the best response.0
yes it would be
 one year ago

jim_thompson5910Best 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 ?
 one year ago

jim_thompson5910Best 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
 one year ago

octoberchick1011Best ResponseYou've already chosen the best response.0
You would make the 2 a zero my by multiplying it by 0..? I think..
 one year ago

jim_thompson5910Best ResponseYou've already chosen the best response.0
well if you did that, everything in row 2 would become 0
 one year ago

jim_thompson5910Best ResponseYou've already chosen the best response.0
then you'd get 0x + 0y = 0...which is completely useless now
 one year ago

octoberchick1011Best ResponseYou've already chosen the best response.0
Oh. That's true..
 one year ago

jim_thompson5910Best ResponseYou've already chosen the best response.0
Instead, you can add/subtract multiples of row 1 to row 2
 one year ago

octoberchick1011Best ResponseYou've already chosen the best response.0
So does that mean we would subtract 2 from row 2?
 one year ago

jim_thompson5910Best ResponseYou've already chosen the best response.0
Notice in the first column we have 1 2
 one year ago

jim_thompson5910Best 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
 one year ago

octoberchick1011Best ResponseYou've already chosen the best response.0
Okay. So does that mean that row 2 looks like this now: 0 6  26
 one year ago

jim_thompson5910Best ResponseYou've already chosen the best response.0
6  2*(3) = 12 so the 2nd element in row 2 is 12
 one year ago

octoberchick1011Best ResponseYou've already chosen the best response.0
Ugh, I'm so confused  lol, these kinds of probles frustrate me! :P
 one year ago

jim_thompson5910Best ResponseYou've already chosen the best response.0
26  2*17 = 60
 one year ago

jim_thompson5910Best ResponseYou've already chosen the best response.0
so the 3rd element in row 2 is 60
 one year ago

jim_thompson5910Best ResponseYou've already chosen the best response.0
after this, you should have 1 3  17 0 12  60
 one year ago
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