cramer’s rule pdf

kramer rule matrix

Cramer’s rule PDF

consider the following system of equation.

a.x + b y = m………………..1

c x +d y =n…………………….2

kramer rule matrix

We know that

AX = B

Where

cramer,s rule pdf proof

Ax =B can be written as

cramer's rule pdf

also, this form can be written as

\large X= \frac{AdjA}{|A|}\, \times \, \, B

Also, can be written as in the form

cramer'rule pdf proof

cramer's rule pdf

cramer rule pdf proof where x equal to

cramer's rule pdf proof where y equal to

this complete the proof of crammer’s rule

Cramer’s rule PDF:

Example:

we solve the following system by using matrix inversion method

4x-2y=8

3x+y=-4

SOLUTION:

STEP: 1

cramer's rule pdf

STEP: 2

the coefficient of matrix  cramer's rule pdf

det M= 4×1-3(-2)= 4+6=10 ≠ 0

SO

\large M^{-1} is possible

STEP : 3

cramer's rule pdf

\large =\frac{1}{10}\begin{bmatrix} 8-8\\ -24-26 \end{bmatrix}

\large =\frac{1}{10}\begin{bmatrix} 0\\ -40 \end{bmatrix}=\begin{bmatrix} 0\\ -4 \end{bmatrix}

hence

\large \begin{bmatrix} x\\ y \end{bmatrix}=\begin{bmatrix} 0\\ -4 \end{bmatrix}

there is

x=0     and   y = -4

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