SOLUTION: Solve the following system of equations by reducing the augmented matrix. 7x + 9y = −49 14x − 5y = 63 (x,y)=

Algebra ->  Finite-and-infinite-sets -> SOLUTION: Solve the following system of equations by reducing the augmented matrix. 7x + 9y = −49 14x − 5y = 63 (x,y)=      Log On


   

Question 1126728: Solve the following system of equations by reducing the augmented matrix.
7x + 9y = −49
14x − 5y = 63
(x,y)=
Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
The augmented matrix is
:
7 9 -49
14 -5 63
:
now perform row operations on the augmented matrix
:
divide row 2 by 2 and subtract from row 1
:
7 9 -49
0 11.5 -80.5
:
divide row 2 by 11.5
:
7 9 -49
0 1 -7
:
multiply row 2 by 9 and subtract row 1 from row 2
:
-7 0 -14
0 1 -7
:
divide row 1 by -7
:
1 0 2
0 1 -7
:
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x = 2 and y = -7
:
check answer in equations
:
equation 1
:
7(2) +9(-7) = -49
:
-49 = -49
:
equation 2
:
14(2) -5(-7) = 63
:
63 = 63
:
answer checks
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