SOLUTION: Solve the equation 2x−9y+5z=−1. in the form _ |x| [] [] [] |y|= [] +[]s +[]t |z| [] [] [] - I have gotten in about 3/4 steps but seem

Algebra ->  College  -> Linear Algebra -> SOLUTION: Solve the equation 2x−9y+5z=−1. in the form _ |x| [] [] [] |y|= [] +[]s +[]t |z| [] [] [] - I have gotten in about 3/4 steps but seem      Log On


   



Question 629330: Solve the equation
2x−9y+5z=−1.
in the form
_
|x| [] [] []
|y|= [] +[]s +[]t
|z| [] [] []
-
I have gotten in about 3/4 steps but seem to get stuck. Would appreciate some help.
Thanks!

Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
2x - 9y + 5z = -1

The smallest coefficient in absolute value is 2

Write each positive integer in terms of its nearest 
smaller multiple of 2

2x - (8+1)y + (4+1)z = -(0+1)

Distribute

2x - 8y - y + 4z + z = -1

Divide every term by 2

x - 4y - y%2F2 + 2z + z%2F2 = -1%2F2

Isolate fractions on the right

x - 4y + 2z = y%2F2 - z%2F2 - 1%2F2

Let that equal to s

y%2F2 - z%2F2 - 1%2F2 = s

Multiply through by 2

y - z - 1 = 2s

Solve for y:

        y = 1 + 2s + z

Let z = t

        y = 1 + 2s + t

Substitute in the original:

2x - 9y + 5z = -1

2x - 9(1 + 2s + t) + 5t = -1

2x - 9 - 18s - 9t + 5t = -1

2x - 9 - 18s - 4t = -1

2x = 8 + 18s + 4t

 x = 4 + 9s + 2t

So:

 x = 4 + 9s + 2t
 y = 1 + 2s +  t
 z =           t

Edwin