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Cramer’s Rule for solving linear systems Part 1 . Fundamentals of Engineering Analysis . Eng. Hassan S. Migdadi. Coefficient Matrices. You can use determinants to solve a system of linear equations. You use the coefficient matrix of the linear system.
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Cramer’s Rule for solving linear systems Part 1 Fundamentals of Engineering Analysis Eng. Hassan S. Migdadi
Coefficient Matrices You can use determinants to solve a system of linear equations. You use the coefficient matrix of the linear system. Linear SystemCoeff Matrix ax+by=e cx+dy=f
Cramer’s Rule for 2x2 System Let A be the coefficient matrix Linear SystemCoeff Matrix ax+by=e cx+dy=f If detA 0, then the system has exactly one solution: and
Example 1- Cramer’s Rule 2x2 Solve the system: 8x+5y=2 2x-4y=-10 The coefficient matrix is: and So: and
Example 2- Cramer’s Rule 2x2 Solve the system: 2x+y=1 3x-2y=-23 The solution is: (-3,7) !!!
Example 3- Cramer’s Rule 3x3 Solve the system: x+3y-z=1 -2x-6y+z=-3 3x+5y-2z=4 Let’s solve for Z Z=1 The answer is: (-2,0,1)!!!
Example: 2x + y + z = 3 x – y – z = 0 x + 2y + z = 0
Determinants of XYZ =3 X= 1, y =-2, z=3 =3 =-6 =9
Given the following system of equations, find the value ofz. 2x + y + z = 1 x – y + 4z = 0 x + 2y – 2z = 3 =-3 =-6 Z=2