What is the solution of the system of equations?
3x+2y+z=7
5x+5y+4z=3
3x+2y+3z=1

Question

What is the solution of the system of equations?
3x+2y+z=7
5x+5y+4z=3
3x+2y+3z=1

anonymous · Answer

@SolomonZelman

solomonzelman · Answer

3x+2y+z=7
5x+5y+4z=3
3x+2y+3z=1

take the first and last equations and subtract them from each other

3x+2y+z=7  -   3x+2y+3z=1

3x-3x   2y-2y   z-3z   =  7-1
so -2z=6  therefore z=-3

plug the z into the all of the equation
3x+2y+(-3)=7
5x+5y+4(-3)=3
3x+2y+3(-3)=1

3x+2y+=10
5x+5y+(-12)=3
3x+2y+(-9)=1

3x+2y+=10
5x+5y+=15
3x+2y+=10

the 1st and last equations are the same so take out one of them, remains

3x+2y+=10
5x+5y+=15

Can you solve it from there?

solomonzelman · Answer

@caitlynnbaby, can you solve it from there on your own?