Verified answer

1) 5/x +4/(x -3)=3

5(x-3)+4x=3x(x-3)

3x^2-18x+15=0

D=16

x1=1

x2=5

2) 3/x  - 3/(x+4)=1

   3(x+4) -3x=x(x+4)

   x^2+4x+12=0

D=64

x1=-6

x2=2

1)5/x+4/x-3=3 |*x

5+4-3x=3x

9=6x

x=1,5

2)3/x-3/x+4=1 |*x

3-3+4x=x

3x=0

x=0