Question

Solve the system of equations.

3x+3y+6z=3
3x+2y+6z=7
4x+4y+7z=4

Answer 1

A

Explanation:

EDGE

Answer 2

`(1)\ 3x+3y+6z=3\\ (2) \ 3x+2y+6z=7\\(3)\ 4x+4y+7z=4\\\\(1)\ -\ (2)\\\Rightarrow\ \ \ 3x+3y+6z-(3x+2y+6z)=3-7\\\\3x+3y+6z-3x-2y-6z=-4\\y=-4\\\\4\cdot (1)\ -3\cdot(3)\\\Rightarrow\ \ \ 4\cdot(3x+3y+6z)-3\cdot(4x+4y+7z)=4\cdot3-3\cdot4\\\\12x+12y+24z-12x-12y-21z=12-12\\3z=0\ /:3\\z=0\\\\`


`(1)\ 3x+3y+6z=3\ /:3\\\\ x+y+2z=1\\\\y=-4\ \ \ and\ \ \ z=0\\ \Rightarrow\ \ \ x-4+2\cdot0=1\ \ \ \Rightarrow\ \ \ x=1+4\ \ \ \Rightarrow\ \ \ x=5\\\\Ans.\ x=5,\ y=-4,\ z=0`