If it's not what You are looking for type in the equation solver your own equation and let us solve it.
D( x )
100*x = 0
100*x = 0
100*x = 0
100*x = 0 // : 100
x = 0
x in (-oo:0) U (0:+oo)
0.9 = (360*(100-x))/(100*x) // - (360*(100-x))/(100*x)
0.9-((360*(100-x))/(100*x)) = 0
(-18/5)*x^-1*(100-x)+0.9 = 0
0.9-18/5*x^-1*(100-x) = 0
0.9-18/5*x^-1*(100-x) = 0
4.5-360*x^-1 = 0
4.5-360*x^-1 = 0
-360*x^-1 = -4.5 // : -360
x^-1 = 0.0125
-1 < 0
1/(x^1) = 0.0125 // * x^1
1 = 0.0125*x^1 // : 0.0125
80 = x^1
x = 80
x = 80
| (20x^4y^-3/17x^-2y)(34x^-3y/30y^-2) | | 7x-21-3x=5+x-4 | | 2x+3y=100000 | | 4(4r-5)=2(5+5r) | | 99*165x=x | | 4x+2x-5+3x=23 | | 15x+26x=-80 | | 5x-4=2x+25 | | 7x+5+x-2=4x+21 | | 3w^2-1w-45=0 | | x(3x-8)=48 | | 6-2y+y=4 | | k^2-4k+12=0 | | 25/100=5/x | | 14/42=22/x | | 0.3/24=x/48 | | ln(2x+1)-ln(x-1)=lnx | | 5x=380-42x | | 6a^2+9a-81=0 | | 6x^2-3x+11=0 | | (2x+1)+(3x-4)=12 | | 10x=100y | | 2x-1/34x-5/5 | | 3p-2q=6 | | 25-3t=4(2t-5)-8t | | c-3=6c-48 | | (x+5)(x+15)= | | 2cos^2x-1=1/2 | | 4x^2-23x+27=0 | | 20n+7=12n | | 5x-13=8x+6 | | (X-5)*(x^2+3)=0 |