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 = 0
x = 0
x = 0
x in (-oo:0) U (0:+oo)
20/60 = 10/x // - 10/x
20/60-(10/x) = 0
20/60-10*x^-1 = 0
-10*x^-1 = -1/3 // : -10
x^-1 = 1/30
-1 < 0
1/(x^1) = 1/30 // * x^1
1 = 1/30*x^1 // : 1/30
30 = x^1
x = 30
x = 30
| 2/3r=66 | | 6x-3(4x-5)=4x-11 | | x-2/5=0 | | 3x-4=5x+7 | | -8(4x-2)=20 | | 90+(3p-6)=180 | | -(x-2)=9 | | -4-h=0 | | 3r+9=12 | | 25+0.16x=18.76 | | 90+(x-50)=180 | | -2(-8n+4)=6(n+2) | | b-18.3=4.67 | | n/6=120 | | m+5=17 | | -13=7+4y | | 8r-9=31 | | x^5-5x^4-240=0 | | 4(2x+1)-3(x-2)=1-2(x-6) | | 7h+31=59 | | 3x1/4 | | 8t^2+5=0 | | 6v+42=8(v+3) | | 2(-5x+4)=32 | | k-5/4=8 | | b/8-6=12 | | x+1-9.79=0 | | y=100x-40x^2 | | -k-6=6-5k | | 7x-8=3x+51 | | 15/y=5/6 | | 9x+5Y=53.55 |