Question 34777
CREATING A MATRIX WE GET

1  1  1
        
0  1  1 OR1(2-0)-1(0-0)+1(0-0)OR 1*2-1*0+1*0 OR 2-0=0 OR 2 IS THE DENOMINATOR
        
0  0  2

FOR X WE GET 

5  1  1

1  1  1 OR 5(2-0)-1(2-4)+1(0-4) OR 10+2-4 OR 8 DIV BY 2 WE GET 8/2=4 FOR X

4  0  2

FOR Y WE GET

1  5  1

0  1  1 OR 1(2-4)-5(0)+1(0)OR -2-5*0+1*0 OR -2 DIV BY 2 WE GET 2/-2=-1 FOR Y

0  4  2

FOR Z WE GET

1  1  5

0  1  1 OR 1(4-0)-1(0)+5(0) OR 4-0+0 OR 4 DIV BY 2 WE GET 2 FOR Z   

0  0  4 

THUS X=4, Y=-1 & Z=2


X+Y=1 & 2X+3Y=0 THEN X=1-Y SUBSTITUTING 1-Y FOR X IN EQUATION TWO WE GET

2(1-Y)+3Y=0 OR 2-2Y+3Y=0 OR 2+Y=0 OR Y=-2 THEN X=1-(-2) OR X=3