SOLUTION: 8x+9y=1 -2x+6y=5 solve this matrix. I am the older sister, who hasnt done matrix stuff since high school. I am trying to remember how to solve this equation. can you please help

Algebra ->  Matrices-and-determiminant -> SOLUTION: 8x+9y=1 -2x+6y=5 solve this matrix. I am the older sister, who hasnt done matrix stuff since high school. I am trying to remember how to solve this equation. can you please help      Log On


   



Question 60374: 8x+9y=1
-2x+6y=5 solve this matrix. I am the older sister, who hasnt done matrix stuff since high school. I am trying to remember how to solve this equation. can you please help. sorry i didnt try, i doont have a book or anything.

Answer by kayeith(17) About Me  (Show Source):
You can put this solution on YOUR website!
8x + 9y = 1
- 2x + 6y = 5
a = 8 b = 9 c = 1
d = - 2 e = 6 f = 5
D = ae - db = (8)(6) - (-2)(9) = 48 + 18 = 66
Dx = ce - fb = (1)(6) - (5)(9) = 6 - 45 = - 39
Dy = af - dc = (8)(5) - (-2)(1) = 40 + 2 = 42
x = Dx / D = -39 / 66 = -13 / 22
y = Dy / D = 42 / 66 = 11 / 33