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)
1/x = 0.2/8 // - 0.2/8
1/x-(0.2/8) = 0
1/x-0.025 = 0
1*x^-1 = 0.025 // : 1
x^-1 = 0.025
-1 < 0
1/(x^1) = 0.025 // * x^1
1 = 0.025*x^1 // : 0.025
40 = x^1
x = 40
x = 40
| 2x+4y=224 | | x^3+3x^2=5 | | kx-2y+9=0 | | 8/9d=5/6 | | 13000+25000x=27500 | | x^2-5+41=0 | | 8x+24y= | | 7m^2+11m-6=0 | | x^2-3+41=0 | | 3(x+4)=x+6-2 | | (x+10)5=100 | | x^2/2+5/2x=2 | | -5+4=-3 | | x^2-4+41=0 | | x+1/3=7/9 | | x^2-2+41=0 | | 160=r^2*4 | | x/6+7=10 | | 5y+1+2y=-15 | | 13x-23=4x+31 | | 160=r^2h | | 3y-6=2y+6 | | 12x+4=-20 | | x=73163 | | 8n-5=13n-9 | | 3(8-6x)-5(10-11x)=233 | | 8=6/4+b | | -136-5x=44-11x | | c=23.145 | | 2y-14=-12+3y | | 8x-2(3x-5)=40 | | x-8.4=-6.2 |