SOLUTION: 9x + 1y = 38 -5x - 4y = 3 write the augmented matriz for the linear system and then solve

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Question 17091: 9x + 1y = 38
-5x - 4y = 3
write the augmented matriz for the linear system and then solve
Answer by venugopalramana(3286) About Me  (Show Source):
You can put this solution on YOUR website!
9x + 1y = 38
-5x - 4y = 3
augmented matrix is obtained by joining the numerals on the right hand side of the equations (38 and 3)as an additional column to the coefficient matrix formed by using the coefficients of x and y on the left hand side of the equations ..it is =
matrix%282%2C3%2C9%2C1%2C38%2C-5%2C-4%2C3%29
we have to bring the augmented matrix into the form
matrix%282%2C3%2C1%2C0%2Ca%2C0%2C1%2Cb%29by appropriate transformation ,when we get the solution as x=a and y=b..i hope you know the procedure ..i am giving the stepsbelow with the transformation used..
start matrix%282%2C3%2C9%2C1%2C38%2C-5%2C-4%2C3%29
new R1=oldR1/9..here after abbreviated as NR1=OR/9...
matrix%282%2C3%2C1%2C1%2F9%2C38%2F9%2C-5%2C-4%2C3%29
NR2=OR2+5*OR1...note that here old R1 refers to already modified row in the above matrix
matrix%282%2C3%2C1%2C1%2F9%2C38%2F9%2C0%2C%28-4%2B5%2F9%29%2C%283%2B5%2A38%2F9%29%29
NR2=OR2*(-9/31)
matrix%282%2C3%2C1%2C1%2F9%2C38%2F9%2C0%2C1%2C%28-9%2F31%29%2A%28217%2F9%29%29
NR1=OR1-OR2*(1/9)

on simplifying
matrix%282%2C3%2C1%2C0%2C5%2C0%2C1%2C-7%29
hence x=5 and y=-7..you can check by substitution in the original equations.