This is an alternate method of finding the Inverse Matrix;
Any 2 rows can be interchanged
Any row/column can be multiplied by a non-0 constant
Any row/column can be replaced by itself, plus any other row/column multiplied by a non-zero constant
Any row/column can be replaced by itself multiplied by a non-0 constant, plus any other row/column multiplied by a different non-0 constant
NB: This is called a Row Reduced Matrix
The number of 0's preceding the 1st non-0 entry increases row by row.NB: Try to make as many 0 terms as possible.
After expressing in the correct form, use Row Reduction methods on both sides to change the matrix into Echelon Form.For a 3x3 matrix, try to get either Row 2 or Row 3 to have 2 0's as this will make it easier to find either y or z.Then substitute this answer into the other equations to find x and either y or z (whichever one you didn't find 1st).
Two LinesConsider 2 straight lines ax+by=m and cx+dy=n then;
If the lines are parallel, then there are no solutions and the equations are inconsistant
2 lines will intersect at one unique point
If the 2 lines are the same, there are an infinate number of solutions
Three Linesax+by+m=0cx+dy+n=0ex+fy+p=0These are consistant if the determinant = 0
Equations with 3 Unknowns
ax+by+cz=m is the equation of a planeax+by+cz=m and ax+by+cz=n where m≠n represent parallel planesIf 2 equations are multiples of each other, then they represent the same planeNB: Solving a set of 3 equations with 3 unknowns is finding where the 3 planes, represented by the 3 equations, intersect.