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raebaby420
Group Title
Use the substitution method to solve the following system of equations.
x + 2y – z = 7
4x – y + 3z = –2
2x + 2y – z = 9
 one year ago
 one year ago
raebaby420 Group Title
Use the substitution method to solve the following system of equations. x + 2y – z = 7 4x – y + 3z = –2 2x + 2y – z = 9
 one year ago
 one year ago

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Zelda Group TitleBest ResponseYou've already chosen the best response.2
Well, here we go: First let's set the first equation equal to: – z = 7  x  2y Which becomes: z = x+2y  7 okay?
 one year ago

Zelda Group TitleBest ResponseYou've already chosen the best response.2
No put this in equation #2: 4x – y + 3z = –2 Becomes: 4x – y + 3(x+2y  7) = –2 Which becomes: 4x  y +3x +2y 21 = 2
 one year ago

Zelda Group TitleBest ResponseYou've already chosen the best response.2
With me so far?
 one year ago

raebaby420 Group TitleBest ResponseYou've already chosen the best response.0
Yes kinda
 one year ago

Zelda Group TitleBest ResponseYou've already chosen the best response.2
So, then we combine like terms to get: 4x  y +3x +2y 21 = 2 7x + y 21 = 2 y = 7x +19 And finally put this in the third equation and solve for x. So put in the first and second equations into the third one and solve for x.
 one year ago

raebaby420 Group TitleBest ResponseYou've already chosen the best response.0
Im not sure
 one year ago

Zelda Group TitleBest ResponseYou've already chosen the best response.2
So we have z = x+2y  7 and we have y = 7x +19 SO in the third equation: 2x + 2y – z = 9 Wherver you see a z, put that equation, and where you see a y, put in the equation for y. (First put in the y in the z equation)
 one year ago

raebaby420 Group TitleBest ResponseYou've already chosen the best response.0
I got it! thanks!!
 one year ago

Zelda Group TitleBest ResponseYou've already chosen the best response.2
No problem kiddo.
 one year ago
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