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)
380/425 = 500/x // - 500/x
380/425-(500/x) = 0
380/425-500*x^-1 = 0
-500*x^-1 = -76/85 // : -500
x^-1 = 19/10625
-1 < 0
1/(x^1) = 19/10625 // * x^1
1 = 19/10625*x^1 // : 19/10625
10625/19 = x^1
x = 10625/19
x = 10625/19
| 76/85=500/x | | 44=B-10 | | 19/25=500/x | | 8E=(-80) | | G/4=16 | | -14=(-2F) | | 5x/4*2/3x= | | 10+C=(-17) | | 2(6m+3n)= | | 7x-2y+137-9x= | | d-(-33)=28 | | 7x+18=5x-12 | | -12(2-v)+3=-8v+19 | | 5(3s+r)= | | -15+0.39=50 | | 4(3a-3)= | | 3=(x*1.10)+((x+.52)*1.25) | | 11k+(-13k)-(-k)-1=5 | | 9x+4y=5000 | | 15m-4m+m-m-1=15 | | m^2-6m-40=0 | | (-11p)-(-4p)+4p=(-15) | | 7(r-825)=476 | | 12r-4r-6r-r+2=9 | | 10g+(-19g)+8g=17 | | 182=4x-6(3x-13) | | 6+1/7=9 | | cosx-cotx=0 | | 10+9/3 | | 9m+9m-13m-m=31 | | 2m^2=8-6m | | 74-c=63 |