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)
4/x = (18/5)*x+2 // - (18/5)*x+2
4/x-((18/5)*x)-2 = 0
(-18/5)*x+4/x-2 = 0
4*x^-1-18/5*x^1-2*x^0 = 0
(4*x^0-18/5*x^2-2*x^1)/(x^1) = 0 // * x^2
x^1*(4*x^0-18/5*x^2-2*x^1) = 0
x^1
(-18/5)*x^2-2*x+4 = 0
(-18/5)*x^2-2*x+4 = 0
DELTA = (-2)^2-(4*4*(-18/5))
DELTA = 308/5
DELTA > 0
x = ((308/5)^(1/2)+2)/(2*(-18/5)) or x = (2-(308/5)^(1/2))/(2*(-18/5))
x = -5/36*((308/5)^(1/2)+2) or x = -5/36*(2-(308/5)^(1/2))
x in { -5/36*((308/5)^(1/2)+2), -5/36*(2-(308/5)^(1/2))}
x in { -5/36*((308/5)^(1/2)+2), -5/36*(2-(308/5)^(1/2)) }
| -3x^2+5x+6=x | | 3m-2/5=4-m/3 | | 6p=12-10.4 | | 5.8q-1.8-4.9q=0.1q-2.4 | | 2k+k=109 | | x/12=x/13-5 | | xsquared-16x+48= | | 6-3(6x-5)=-6 | | x^4+sqrt(52)x^2-52=0 | | -5x-4+3x=36 | | 1/8(24y+16)-9=-1/4(4y-36) | | 2n-3n-20= | | 15x+(-6x+5)-2-(-x+3)=-(7+23)-x+(3-2x) | | 114+x=5x-42 | | 9*7/4=12+x | | -4x/6=2 | | -6x-3=21 | | 3m/4+6=33 | | 9k=12+x | | -x+7/2=2 | | -1/15k=17 | | 5x-6y=48 | | 5.8q-1.8-4.9=-0.1q-2.4 | | 9x+7y=49 | | 1=x-7 | | -11/7k=2 | | x^2=(-81) | | 3x^4/3+5=53 | | 10/3x=-4 | | 3/6+2/9=x | | 3/9+2/3=x | | 8x-7=-7 |