Posted by cody on Wednesday, September 21, 2011 at 6:52pm.
well i'm stumped. i can't figure out how to solve this.
solve for (x,y):
3/x + 2/y = 0
5/x  1/y = 13
i can't graph it, and i can't use a calculator. i keep getting stuck on the second equation b/c i get 5y 13xy x=0 and since 13 is a prime number i cant figure out what to do next.

algebra  Reiny, Wednesday, September 21, 2011 at 7:29pm
first:
3/x + 2/y = 0
times xy
3y + 2x = 0
y = 2x/3
in 2nd:
times xy
5y  x = 13xy
sub in y = 2x/3
5(2x/3)  x = 13x(2x/3)
10x/3  x = 26x^2/3
times 3
10x  3x = 26x^
26x^2  13x = 0
13x(2x  1) = 0
x = 0 or x = 1/2
but x cannot be zero or else we divided by zero in each equation, that would be undefined
x = 1/2
then y = (2/3)(1/2) = 1/3