SOLUTION: What is the value of "z" in the solution of this system? I need the work to be shown because i don't understand others like this.
2x+3y+2z=2
x-4y+6z=-25
3x+5y-4z=25
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-> SOLUTION: What is the value of "z" in the solution of this system? I need the work to be shown because i don't understand others like this.
2x+3y+2z=2
x-4y+6z=-25
3x+5y-4z=25
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Question 745029: What is the value of "z" in the solution of this system? I need the work to be shown because i don't understand others like this.
2x+3y+2z=2
x-4y+6z=-25
3x+5y-4z=25 Answer by josgarithmetic(39618) (Show Source):
Third equation
substitute for x,
3(4y-6z-25)+5y-4z=25
12y-18z-75+5y-4z=25
First equation
substitute for x,
2x+3y+2z=2
2(4y-6z-25)+3y+2z=2
8y-12z-50+3y+2z=2
Use the now simpler system
17y-22z=100
11y-10z=52
---------
17y=100+22z
y=(100+22z)/17
and
11y=52+10z
y=(52+10z)/11
Equating equal expressions of y,
(100+22z)/17=(52+10z)/11
11(100+22z)=17(52+10z)
1100+242z=884+170z
1100-884=(170-242)z
216=-72z
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