SOLUTION: 9x-9y=9 7y-3x=-5 This one is supposed to be solved by the elimination method the solution is an ordered pair, and I am really stumped, can someone help pleeese!!Thank You.

Algebra ->  Linear-equations -> SOLUTION: 9x-9y=9 7y-3x=-5 This one is supposed to be solved by the elimination method the solution is an ordered pair, and I am really stumped, can someone help pleeese!!Thank You.      Log On


   

Question 245800: 9x-9y=9
7y-3x=-5
This one is supposed to be solved by the elimination method
the solution is an ordered pair, and I am really stumped, can someone help pleeese!!Thank You.
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
You have two unknowns and two equations:
9x-9y=9
7y-3x=-5
.
Reordering the second equation:
9x-9y=9
-3x+7y=-5
.
The idea is to combine (add) both equations together to get rid of one of the unknowns.
.
We start by multiplying the second equation by 3:
9x-9y=9
3(-3x+7y)=3(-5)
.
9x-9y=9
-9x+21y=-15
.
Now, we add the two equations together:
9x-9y=9
-9x+21y=-15
------------
12y=-6
y = -6/12
y = -1/2
.
Substitute the above into our original first equation:
9x-9y=9
9x-9(-1/2)=9
9x-(-9/2)=9
9x+9/2=9
x+1/2=1
x = 1-1/2
x = 1/2
.
Solution:
(x,y) = (1/2, -1/2)