If it's not what You are looking for type in the equation solver your own equation and let us solve it.
D( x )
x-3 = 0
x^2-9 = 0
x-3 = 0
x-3 = 0
x-3 = 0 // + 3
x = 3
x^2-9 = 0
x^2-9 = 0
1*x^2 = 9 // : 1
x^2 = 9
x^2 = 9 // ^ 1/2
abs(x) = 3
x = 3 or x = -3
x in (-oo:-3) U (-3:3) U (3:+oo)
(2*x)/(x^2-9)-(1/(x-3)) = 0
(2*x)/(x^2-9)-(x-3)^-1 = 0
(2*x)/(x^2-9)-1/(x-3) = 0
(2*x*(x-3))/((x^2-9)*(x-3))+(-1*(x^2-9))/((x^2-9)*(x-3)) = 0
2*x*(x-3)-1*(x^2-9) = 0
x^2-6*x+9 = 0
x^2-6*x+9 = 0
x^2-6*x+9 = 0
DELTA = (-6)^2-(1*4*9)
DELTA = 0
x = 6/(1*2)
x = 3 or x = 3
(x-3)^2 = 0
((x-3)^2)/((x^2-9)*(x-3)) = 0
((x-3)^2)/((x^2-9)*(x-3)) = 0 // * (x^2-9)*(x-3)
(x-3)^2 = 0
x-3 = 0 // + 3
x = 3
x in { 3}
x belongs to the empty set
| 16*x^2-66*x+65=0 | | d-0.9=11 | | Y-6.8=12.19 | | 5x*344= | | K+-940=-556 | | X-3/5=21 | | 5(2+d)=45 | | Q-559=92 | | X^1/2-4=1 | | 0.4x+6=.75x-8 | | 3/5=21-x | | 235*-2x= | | 3(t-1)=3(2t-3) | | Y-95=537 | | 4x+25=2x+23 | | 115=5(3-4x) | | 3x+13=4-6x | | 6(x+9)+X=3(x+3)+6 | | J+420=782 | | -6+4z-z=-24 | | 11s-10s+2=14 | | U+-97=-31 | | 3t+30=6 | | 78=q+10 | | -6+4z-z=-2 | | 9y+2+7x+18+3y+2x+5= | | 98=7k | | 4n=14.4 | | W-34=33 | | (10x-2)/2 | | 4=18(n-1) | | 4x+14=7x+23 |