SOLUTION: Write the system of equations as an augmented matrix. Then solve for x and y. -x+4y=11 -2x+y=8

Algebra ->  Probability-and-statistics -> SOLUTION: Write the system of equations as an augmented matrix. Then solve for x and y. -x+4y=11 -2x+y=8      Log On


   

Question 1055061: Write the system of equations as an augmented matrix. Then solve for x and y.
-x+4y=11
-2x+y=8
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
%28matrix%282%2C3%2C%0D%0A-1%2C4%2C11%2C%0D%0A-2%2C1%2C8%29%29
Use the row operation -2R%5B1%5D%2BR%5B2%5D to replace R%5B2%5D,
%28matrix%282%2C3%2C%0D%0A-1%2C4%2C11%2C%0D%0A0%2C-7%2C-14%29%29
Replace R%5B2%5D with -%281%2F7%29R%5B2%5D,
%28matrix%282%2C3%2C%0D%0A-1%2C4%2C11%2C%0D%0A0%2C1%2C2%29%29
Replace R%5B1%5D with R%5B1%5D-4R%5B2%5D,
%28matrix%282%2C3%2C%0D%0A-1%2C0%2C3%2C%0D%0A0%2C1%2C2%29%29
Replace R%5B1%5D with -R%5B1%5D,
%28matrix%282%2C3%2C%0D%0A1%2C0%2C-3%2C%0D%0A0%2C1%2C2%29%29
So,
x=-3
y=2