How do you solve -x + y + z = -1x+y+z=1 and -x + 5y - 15z = -13x+5y15z=13 and 3x - 2y - 7z = 03x2y7z=0 using matrices?

1 Answer
Feb 22, 2016

This is a impossible system of equations and has no solution.

Explanation:

Delta=[[-1,1,1],[-1,5, -15],[3,-2,-7]]=35-45+2-(15-30+7)=-8+8=0
Delta x=[[-1,1,1],[-13,5, -15],[0,-2,-7]]=35+0+26-(0-30+91)=61-61=0
Delta y=[[-1,-1,1],[-1,-13, -15],[3,0,-7]]=-91+45+0-(-39-7+0)=-46+46=0
Delta z=[[-1,1,-1],[-1,5, -13],[3,-2,0]]=0-39-2-(15-26+0)=-41+11=-10

Since Delta =0 but Delta z !=0 this system of equations is a impossible one and has no solution.