one more solving systems

[Guest]

i need to solve the system for x y and z:

3x+5y+3z=2
6x+5y+z=0
3x+10y-2z=6

okay so i think im suppose to combine the top two and cancle out y: 9x+4z=2 but then im stuck at how to cancel the y in the 3rd line....PLEASE HELP!
~Sarah~

 

[Denis]

i need to solve the system for x y and z:
3x+5y+3z=2
6x+5y+z=0
3x+10y-2z=6
okay so i think im suppose to combine the top two and cancle out y: 9x+4z=2 but then im stuck at how to cancel the y in the 3rd line....PLEASE HELP!
~Sarah~

NO: you have to SUBTRACT the top 2: 3x - 2z = -2

To cancel y in 3rd, multiply 2nd by 2 to get 12x + 10y + 2z = 0;
now subtract to get 9x + 6z = -6

Ya'll ok now?