Applying Determinants to solve Systems of Equations 2x2 & 3x3 Cramer’s Rule Applying Determinants to solve Systems of Equations 2x2 & 3x3
2x2 Determinants Det A = ad – cb
Cramer’s Rule for 2x2 Part 1 1. Extract Coefficients 2. Calculate Determinant of Original Matrix
Cramer’s Rule for 2x2 Part 2 (Solving for x) Replace the 1st column of the coefficient matrix with the constant matrix. Calculate the determinant of new matrix & divide by original determinant.
Cramer’s Rule for 2x2 Part 3 (Solving for y) Replace the 2nd column of the coefficient matrix with the constant matrix. Calculate the determinant of new matrix & divide by original determinant.
Cramer’s Rule for 2x2 Part 4 To check x and y, substitute 51 in for x and 30 in for y.
Ex #4 Solve
3x3 Determinants
Cramer’s Rule for 3x3 Part 1 Extract coefficients. Calculate Original Determinant (OD) of Matrix
Cramer’s Rule for 3x3 Part 2 (Solving for x) Replace the 1st column of the coefficient matrix with the constant matrix. Calculate the determinant of new matrix & divide by original determinant (15).
Cramer’s Rule for 3x3 Part 3 (Solving for y) Replace the 2nd column of the coefficient matrix with the constant matrix. Calculate the determinant of new matrix & divide by original determinant (15).
Cramer’s Rule for 3x3 Part 4 (Solving for z) Replace the 3rd column of the coefficient matrix with the constant matrix. Calculate the determinant of new matrix & divide by original determinant (15).
Cramer’s Rule for 3x3 Part 5 9. To check x and y, substitute 2.6 in for x, 2.2 in for y, and 0.2 in for z.