SOLUTION: solve using addition method 3/7x+5/9y=27 1/9x+2/7y=7

Algebra ->  Linear-equations -> SOLUTION: solve using addition method 3/7x+5/9y=27 1/9x+2/7y=7      Log On


   



Question 238653: solve using addition method
3/7x+5/9y=27
1/9x+2/7y=7

Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
3X/7+5Y/9=27 MULTIPLY BY 1/9
1X/9+2Y/7=7 MULTIPLY BY -3/7 & ADD
(3X/7)(1/9)+(5Y/9)(1/9)=27(1/9)
(X/9)(-3/7)+(2Y/7)(-3/7)=7(-3/7)
----------------------------------------
3X/27-3X/27+5Y/81-6Y/49=27/9-21/7
5Y/81-6Y/49=3-3
(5Y*49-6Y*81)/81*49=0
245y-486y=0
-241y=0
y=0 ans.
3x/7=27
3x=27*7
3x=189
x=189/3
x=63 ans.
Proof:
63/9+2*0/7=7
7=7