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)
40/x = 1 // - 1
40/x-1 = 0
40*x^-1 = 1 // : 40
x^-1 = 1/40
-1 < 0
1/(x^1) = 1/40 // * x^1
1 = 1/40*x^1 // : 1/40
40 = x^1
x = 40
x = 40
| 2x+(90-x)=x+30 | | -1-5p=-4p-10 | | 121=-5+6(-4x+5) | | V=h(21.78-0.101a) | | f(x)=800(1.09)4 | | -3x+2(x-2)=-14 | | 5x-6=6x-11 | | 26+x=34 | | -2x-5(-x-4)=-1 | | 3y^2+2y-7=0 | | 4x+3(-3x+4)=37 | | -82=-7(2x+5)-5 | | 2cos^2x+5cosx+3=0 | | 21z=12(2z-2) | | 0.15x-4.25=0.5x-2.5 | | Y=2(x+6)(x+3) | | 2x-1=-6x | | 2a+a+5=35 | | -4x+40-x+50=180 | | 6n-14=3n-7 | | 4-10x/10x-5=1 | | 13x-55=10x-25 | | 0.5*5= | | 2x+36=3x-54 | | -r+4.2=8.8r | | 2x-4(-x+3)=36 | | (y+2)2=6 | | 4sin^2x-2sinx=0 | | 3.75/3 | | 5*x/11=-37/8 | | (1-1000x)*2=22 | | 2x+3-3x-223=180 |