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4.6 Cramer’s Rule. Objectives: Solve systems of two linear equations by using Cramer’s Rule Solve systems of three linear equations by using Cramer’s Rule. Cramer’s Rule. Cramer’s rule uses determinants to solve systems of linear equations.
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4.6 Cramer’s Rule Objectives: Solve systems of two linear equations by using Cramer’s Rule Solve systems of three linear equations by using Cramer’s Rule
Cramer’s Rule Cramer’s rule uses determinants to solve systems of linear equations. The solution to the system of linear equations ax+by=e cx+dy=f Is (x, y) where and (replace the variable you are finding with what the equations are equal to, denominator is det. of left side. )
Example Solve 5x+4y=28 3x-2y=8 using Cramer’s rule Solution: (4,2)
Cramer’s Rule for 3 Variables Use the same principle of replacing what you are looking for with what the equations are equal to. Given: ax + by + cz = j dx + ey + fz = k gx + hy + iz = l j b c k e f l h i a j c d k f g l i where a b c d e f g h i x = y = ≠ 0 a b c d e f g h i a b c d e f g h i
Example Solve using Cramer’s rule -5x+y-4z=7 -3x+2y-z=0 2x+3y-z=17 Solution: (3,