Question 535146: I need to find the answer for x,y,and z
3x+2y-2z=5
2y-5z=-7
6x+5y-8z=5
Answer by Iluvidina(15)   (Show Source):
You can put this solution on YOUR website! X=3; y=-1; z=1
First, I used the equation 2y-5z=-7, because it is the equation with the least number of variables
I decided to solve for y
The first thing to do would be add 5z to both sides
The equation would then be 2y=-2z
Then divide each side by 2 to get y by itself
So, the equation would be y=-z
Then, I used the same equation to find z
So, I plugged in -z for y
So the equation would be 2(-z)-5z=-7
Then I multiplied 2 and -z
The equation would then be -2z-5z=-7
then I subtracted -2z and 5z
The equation became -7z=-7
then I divided both sides by -7 getting z alone on one side
So it became z=1
then I plugged z in the equation 2y-5z=-7 to find y
The equation was 2y-5(1)=-7
then I multiplied -5 and 1
So it would be 2y-5=-7
then I added both sides by 5
Then the equation was 2y=-2
then I divided both sides by 2
So y=-1
Then, since I have y and z, I used both of those in the equation 3x+2y-2z=5
i substituted y for -1 and z for 1
So the equation would be 3x+2(-1)-2(1)=5
then I simplified the equation
3x-2-2=5
Then I simplified again
3x-4=5
then I added 4 to both sides
3x=9
then I divided both sides by 3
x=3
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