SOLUTION: 2X-5Y=10 3X+4Y=15 -----------

Algebra ->  Equations -> SOLUTION: 2X-5Y=10 3X+4Y=15 -----------       Log On


   

Question 334363: 2X-5Y=10
3X+4Y=15
------------
Answer by privani(34) About Me  (Show Source):
You can put this solution on YOUR website!
2X-5Y=10 .... (1)
3X+4Y=15 .... (2)
------------ (1)*4 and (2)*5
8X -20Y=40 ...(3)
15X+20Y=75 ...(4)
------------ (3)+(4)
20X = 115
X = 115/20
X = 23/4 ....(5)
Substitute (5) in (1)
2X-5Y=10
2%2823%2F4%29-5Y=10
%2823%2F2%29-5Y=10
-5Y=10-23%2F2
-5Y=%2820-23%29%2F2
Y=%28-3%2F2%29%2F-5
Y=%28-3%2F2%29%2A%28-1%2F5%29
Y=3%2F10