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)
1200/x = 100/15 // - 100/15
1200/x-(100/15) = 0
1200/x-20/3 = 0
1200*x^-1 = 20/3 // : 1200
x^-1 = 1/180
-1 < 0
1/(x^1) = 1/180 // * x^1
1 = 1/180*x^1 // : 1/180
180 = x^1
x = 180
x = 180
| 3(6x+4yi)=9-24i | | g^2+20g+19=0 | | 0=g^2+20g+19 | | 2x+5+4x=4x+18+x | | 6x+24=360 | | 1/2(4x-8)=1/4(-8x-16) | | P(x)=x^3-5x^2+11x-15 | | 2x+19y-344=o | | 5x^2-6=13 | | 2(x-3)=10x-5-8x | | f(-5)=2x^2+3x+5 | | 2(x+140)=430 | | 6a-5ab=0 | | 3t+(t-2)=10 | | Z+4(2z+3)-n=0 | | w/4=-6.4 | | 4000/18=x | | X*x=353 | | cos^2x+5=0 | | 1(-x-2)+-4(x-3)=20 | | 3*a=9 | | 24x^3+2x^2=0 | | f(x)=4x^2+3x+7 | | 100900L=howmanykl | | (2x-15)+x=9 | | x^3-10x^2-13x=0 | | 3+9x=120 | | 5x+3(1+4x)=26-6x | | 12x+8=8x+1+4x | | 3(m+1)-2m=20 | | 80x+40y=400 | | f(2)=2x^2+3x+5 |