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)
m/x = k // - k
m/x-k = 0
m*x^-1 = k // : m
x^-1 = k/m
-1 < 0
1/(x^1) = k/m // * x^1
1 = (k/m)*x^1 // : k/m
1/(k/m) = x^1
x = 1/(k/m)
x = 1/(k/m)
| 25x^2-20x+9=81 | | 6x-3/2x=15 | | 0.333x+0.333=0.666x | | W*2+97=113 | | 30(6x)=40+10x | | 6+(-11.4x)+5.4x=48 | | 4*1-2y=8 | | z=-8-8i | | 5-4j=-7 | | 3cos^2-1=0 | | 8-3k=4k-6 | | 4*2-2=8 | | 7/12÷2/9= | | 12769=1/3*b*31.7 | | 2x-5x+10=-3(x-2) | | 7200// | | 2x=7x-50 | | -36x^3+-8y^3+1=0 | | 11x-15=7x+11 | | 9x-4=8x+4 | | -4d+9=-15+2d | | 7200/10 | | 3y-4+6y+12+4y=180 | | 0.2x^2-0.2x-0.4=0 | | 10=4j-2 | | 2x^2-0.2x-0.4=0 | | 7+x=13+14x | | 12240.788=1/3*b*51.9 | | 50k^2+50k=0 | | 1/6x3/4= | | 5+2n=35+8n | | y=-4x+34 |