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)
12*x+7 = 12/x // - 12/x
12*x-(12/x)+7 = 0
12*x-12*x^-1+7 = 0
12*x^1-12*x^-1+7*x^0 = 0
(12*x^2+7*x^1-12*x^0)/(x^1) = 0 // * x^2
x^1*(12*x^2+7*x^1-12*x^0) = 0
x^1
12*x^2+7*x-12 = 0
12*x^2+7*x-12 = 0
DELTA = 7^2-(-12*4*12)
DELTA = 625
DELTA > 0
x = (625^(1/2)-7)/(2*12) or x = (-625^(1/2)-7)/(2*12)
x = 3/4 or x = -4/3
x in { -4/3, 3/4}
x in { -4/3, 3/4 }
| 5p/3q+4p^2/q | | x-1-3(-4x)=3x-41 | | -48=20v+8v | | 10x+29(x-2)=137 | | k+7=5 | | (x+9)/2=20 | | -2p+7=5(7p+4) | | (x+9)2=20 | | -6x^2-28x+10=0 | | 5/6-1/9 | | 3n+8=2n-5 | | 4.1z=13.81 | | 60=x^2+17x | | 11-5(3x+2)+7x=1-8x | | 45x/5x | | -x^4-11x^2-6=0 | | 24=7y-18 | | 5/12=5d | | -18+24=-2(x+8) | | X/4+10=13 | | 11y-(-8)=-36 | | 4x+3=-4x-5 | | X-4=4x+8 | | 4-0.2x=20 | | 4x^2-23x+31=-3x+10 | | 65.8-24.24= | | -5(4x-4)-2x=3x+45 | | 35/36+18/36 | | -9y-13=59 | | 0=6x^2-13x-5 | | -0.3n-7=-3 | | -2y+12=-20 |