Three variables (unique solution)

> c:=array(1.. 3,1.. 4,[[1,-2,-1,8],[3,-1,2,7],[1,-5,-1,19]]);

> glinsys(c);

Add to row 2 -3 times row 1

> c1:=linalg[addrow](c,1,2,-3);

> glinsys(c1);

Add to row 3 -1 times row 1

> c2:=linalg[addrow](c1,1,3,-1);

> glinsys(c2);

> print(c2);

Multiply row 2 by 1/5

> c3:=linalg[mulrow](c2,2,1/5);

Add to row 1 2 times row 2

> c4:=linalg[addrow](c3,2,1,2);

> glinsys(c4);

Add to row 3 3 times row 2

> c5:=linalg[addrow](c4,2,3,3);

> glinsys(c5);

> print(c5);

Multiply row 3 by /13

> c6:=linalg[mulrow](c5,3,1/3);

Add to row 1 -1 times row 3

> c7:=linalg[addrow](c6,3,1,-1);

> glinsys(c7);

Add to row 2 -1 times row 3

> c8:=linalg[addrow](c7,3,2,-1);

> glinsys(c8);

The point of intersection of the three planes in the picture above is the solution to the orginal system. The next animation reviews the steps used. Can you see the one common point?

> geSlideShow([c,c1,c2,c3,c4,c5,c6,c7,c8]);

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