5x+9y=-30

6x-2y=28

apply matrix technique to solve the following equation
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1 Answer

Create matrix:

⎡ 5  9⎤

⎣ 6 -2⎦

and its determinant D: 5×(-2)-9×6=-10-54=-64; D=-64.

Solution for x requires determinant X=

⎡ -30  9⎤

⎣  28 -2⎦=

(-30)×(-2)-9×28=60-252=-192. x=X/D=-192/-64=3, so x=3.

Solution for y requires determinant Y=

⎡ 5  -30⎤

⎣ 6   28⎦=

5×28-(-30)×6=140+180=320. y=Y/D=320/-64=-5, so y=-5.

CHECK by substitution:

5x+9y=15-45=-30✔️

6x-2y=18+10=28✔️

Other matrix-based solutions are available.
by Top Rated User (1.2m points)

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