SOLUTION: Find a common solution for the system of equations -3y+12x=9 and x-y=0

Algebra ->  Linear-equations -> SOLUTION: Find a common solution for the system of equations -3y+12x=9 and x-y=0      Log On


   

Question 631650: Find a common solution for the system of equations -3y+12x=9 and x-y=0
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
Find a common solution for the system of equations -3y+12x=9 and x-y=0
.
Given:
-3y+12x=9
x-y=0
.
Reorder the first equation:
12x-3y=9
x- y=0
.
Multiply the second equation by -3 and add both equations together:
12x-3y=9
-3x+3y=0
-----------
9x =9
x = 1
.
substitute the above into:
x-y=0
1-y=0
-y=-1
y = 1
.
Answer: x=1 and y=1