2/x+3/y=9/xy,4/x+9/y=21/xy.what is the value of x,y

Answer 1

2/x+3/y = 9/xy can be rewritten
2y + 3x = 9, or
4y + 6x = 18

4/x+9/y = 21/xy can be rewritten
4y + 9x = 21

Now you can eliminate the y unknown:

3x = 3
x = 1
Then solve for y with any equation in x and y.
4y + 6 = 18
4y = 12
y = 3