Решите:
x+5/2x-6=1/4; 2-x/15-x=8; 2/x+3=2x-1/x^2

1) x+5/2x-6=1/4 
2x-6=4*(x+5)
2x-6=4x+20
-2x=26
x=-13

2)2-x/15-x=8
2-x=8*(15-x)
2-x=120-8x
7x=118
x=118/7

3) 2/x+3=2x-1/x^2
2x-1/x^2-2/x=3
2x-1-2x/x^2=3
-1/x^2=3
3x^2=-1
x^2=1/3
x= корень от 1/3