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)
800/x = 3.5 // - 3.5
800/x-3.5 = 0
800*x^-1 = 3.5 // : 800
x^-1 = 0.004375
-1 < 0
1/(x^1) = 0.004375 // * x^1
1 = 0.004375*x^1 // : 0.004375
228.57142857 = x^1
x = 228.57142857
x = 228.57142857
| 2/3(2/5-5x)-3/5=2/5 | | 62=-248 | | 2/3(7/11-3x)-3/11=9/11 | | 4+q=15 | | -4(3-x)=20(x+33) | | 8x+145=3453453 | | X^2+2y-5.25=0 | | (6f^2+7f+6)-(7f+5)= | | 9x-12=2x-45 | | -14/4 | | 36=8x+yx | | (4x-5)=155 | | 144.651=4.5+9.3k | | (125-x^3)=(5-x)(x^2+ax+b) | | 5n+7=0 | | 9x-12=-2x-45 | | -2+n=10 | | 2x-8=46-4x | | 4/x=3/10 | | -112.74=9.2p-9.2 | | 12=15(z−5/1) | | 66/2 | | 4(x-5)-4=3x-5 | | 0.000045=4x^3/0.77 | | 2(x+55)=-2(2-x) | | 7x+7y+11=0 | | 4xsq=44 | | 4.5e-5=4x^3/0.77 | | log(x)=3.1 | | 4x/0.88 | | (2x+5)(x)=250 | | -27=-7(3x+5) |