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)
16/x = x/25 // - x/25
16/x-(x/25) = 0
16*x^-1-1/25*x^1 = 0
(16*x^0-1/25*x^2)/(x^1) = 0 // * x^2
x^1*(16*x^0-1/25*x^2) = 0
x^1
(-1/25)*x^2+16 = 0
(-1/25)*x^2+16 = 0
DELTA = 0^2-(4*16*(-1/25))
DELTA = 64/25
DELTA > 0
x = ((64/25)^(1/2)+0)/(2*(-1/25)) or x = (0-(64/25)^(1/2))/(2*(-1/25))
x = -20 or x = 20
x in { -20, 20}
x in { -20, 20 }
| 3x+5=-4x+15 | | 9n-8=-28+5n | | (3a^4b^6)^2/-9a^8b^10 | | 3n-14=-22+4n | | (-2x^3)(4x^3)= | | (2u^4/4v^2)^3 | | 5cos(2x)-7=-2 | | 15y=12-6x | | 3x+2=(3)2x-1 | | (2x^6/4y^5)^6 | | 3m+4m-9=40 | | 23-5(x-13)=35 | | 81-5yz+4= | | 2lnx=-6 | | X-(x*.2)=186 | | 6x-1.6=-52 | | 2000+6= | | 5m^2-2m=4 | | 2x(x-3)=x^2+2x | | -3x-7x=-80 | | (d^2-d+5)-(2d+5)=equation | | 3x^2+7-x^2-6x+4= | | (7x-8)(5x+8)=0 | | 2x^2-11x+3x^2+11x-4= | | 3x-2ifx=6 | | 9+.5(9+x)=x | | 9+.5(9+x)=y | | y=350+30x | | 45-n=23 | | x^4-2x^3-45x^2-94x-40=0 | | 4x+7-6=5-4x-4 | | (x+20)+2x+133=180 |