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)
36/x = 12/7 // - 12/7
36/x-(12/7) = 0
36/x-12/7 = 0
36*x^-1 = 12/7 // : 36
x^-1 = 1/21
-1 < 0
1/(x^1) = 1/21 // * x^1
1 = 1/21*x^1 // : 1/21
21 = x^1
x = 21
x = 21
| 18=x+y+y | | [X-y]=100 | | 30=x*x*x | | 3n-2=-12 | | 3sinx=tanx | | X/0.4=2.5x | | 6p-10p+2=2p+4 | | 15*x*x=10000 | | 48+4t=282+4t | | 8y+y=72 | | ydx=(x+1)dy | | 24=7u-u | | 1-(8-q)=4*q+3*(3*q-6) | | 15x-7=11x+5 | | 6.6x+2=8.6 | | 15b+2x+13c= | | 30=2r/3 | | 3r-5=r-1 | | y^2/y^2-y-2 | | 8x+15=5x-13 | | 6(3y-1)=-33 | | 6(7-2g)g=3 | | 3p+7=2p+1+x+x | | y-7=5(x-[-2]) | | K=15/45 | | 8x-6=72+4x | | F(m)=50+35m | | 100+11x=260 | | 1*7x=-76 | | -20-2x=2x-4 | | 4x-24+4x=4+8-x | | z^2-15z+4iz+77+105i=0 |