Simplify 1/(1/x+1/y)=6
flip each side and you have
1/x + 1/y = 1/6
6/x + 6/y = 1
6x+6y = xy
Not sure just where you want to go with this.
Clearly, 1/2 + -1/3 = 1/6
1/x + 1/y = 1/6
6/x + 6/y = 1
6x+6y = xy
Not sure just where you want to go with this.
Clearly, 1/2 + -1/3 = 1/6