Math

Use Cramer's Rule to solve: 3x-5y=21 and 4x+2y=2.

a=3, b=-5, c=4, d=2, e=21, f=2
21(2)-(-5)(2) divided by 3(2)-(-5)(4)
=52/26= x=2

3(2)-21(4) divided by 3(2)-(-5)(4)
=78/26= y=3
answer:
(2,3)

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asked by Jon
  1. If you will "plug in" x = 2 and y=3 to either equation, you will see that your solution is incorrect.

    Cramer's rule involves using the determinants of matrices. You do have the denominator determinant (26) correct. The numerator for y is wrong. It should be -78. y = -3

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    posted by drwls

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