Fractions math problem. really easy???

Question

2/? - ?/5= 1/15

thats two over ? minus ? over five equals one fifteenth

u may need to write it down

best answer if u show me how u did it.

Answer 1

assume?=x then

2/x-x/5=1/15   get the l.c.m of left side

(10-x^2)/5x  =1/15   then cross multiply

     10-x^2=(1/15*5x)    =10-x^2=x/3   10=x/3+x/2

get l.c.m  10=(2x+3x)/6   =10=5x/6

  cross so 60=5x   =x=60/5=12

Answer 2

Ok so...

2/? - ?/5 = 1/15

?/15 - ?/15 = 1/15

2/3 - 3/5 = 1/15

10/15 - 9/15 = 1/15

Guessed lol, but I'll figure out an explanation.