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)
200/x = 25 // - 25
200/x-25 = 0
200*x^-1 = 25 // : 200
x^-1 = 1/8
-1 < 0
1/(x^1) = 1/8 // * x^1
1 = 1/8*x^1 // : 1/8
8 = x^1
x = 8
x = 8
| 2x+5y+3x+4y= | | 20=4u-12 | | 7y-2x-5y=4x+8 | | 3x-4+5x+3= | | v=u+t+w | | 3x-36=90 | | 32-10b=-13b-4 | | 7y+5=0 | | 3n+3(-7n+7)=165 | | 1.2=-2.4-3b | | 5x+22-2x=-5 | | cos(pi/2x)=! | | -5(1-7r)+4r=307 | | 2.5+x=5.2+3.2x | | 7x-5y=.9 | | 8x-72=88 | | -88=8(n-3) | | 1.5x+4y=4.2 | | 49/n=7/6 | | 8(2d+5)-3(8d-9)=21 | | 9/n=3/5 | | 2a-1=-4 | | 12/5=b/30 | | -6.3-y=5 | | 9/10=54/r | | -2-2x=-16-4x | | -156=8k-7(7k-7) | | 2/3a-6=12 | | s/21=11/7 | | -2a+24=-6+8a | | s/30=7/10 | | -56+5x=9x+36 |