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)
10/15 = 6/x // - 6/x
10/15-(6/x) = 0
10/15-6*x^-1 = 0
-6*x^-1 = -2/3 // : -6
x^-1 = 1/9
-1 < 0
1/(x^1) = 1/9 // * x^1
1 = 1/9*x^1 // : 1/9
9 = x^1
x = 9
x = 9
| s^2=-38 | | -11.2+4(2.1+q)=-0.6 | | 10/15=x/10 | | 6(8-4f)=24 | | 9+5y=-36 | | 13a+5b=11 | | 51-(3x+15)=3(x+5)+x | | q/5=32 | | 294=12(x+3.50) | | -78=-39p | | 5q^2-90=0 | | 7(a+7)=21-7a | | 55/x=11/9 | | 6m^2+4m+10m-5m=40m^2 | | 2x-(4x+2)=10 | | 7y-2(8y+1)=7 | | 54d^2=24 | | (18x)^1/2 | | 0.4*w=0.65 | | 8+3n-6=6n+4-4n | | 2x+2x-6=-6 | | 8f^2+20=-20 | | (0.5)x+(.10)y=2.50 | | 0.6n+7.56=21 | | D=50-P | | Qd=50-p | | 0.6+7.56=21 | | N^2-21=-20 | | 9x+10-10x=28 | | 20-7x=-7(4x+4)+5x | | 4s-5+2(s+3)+s=148 | | 2a-2=9a-10 |