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^2 = 0
x = 0
x = 0
x^2 = 0
x^2 = 0
1*x^2 = 0 // : 1
x^2 = 0
x = 0
x in (-oo:0) U (0:+oo)
11/x+15/(x^2) = 56 // - 56
11/x+15/(x^2)-56 = 0
11*x^-1+15*x^-2-56 = 0
t_1 = x^-1
15*t_1^2+11*t_1^1-56 = 0
15*t_1^2+11*t_1-56 = 0
DELTA = 11^2-(-56*4*15)
DELTA = 3481
DELTA > 0
t_1 = (3481^(1/2)-11)/(2*15) or t_1 = (-3481^(1/2)-11)/(2*15)
t_1 = 8/5 or t_1 = -7/3
t_1 = -7/3
x^-1+7/3 = 0
1*x^-1 = -7/3 // : 1
x^-1 = -7/3
-1 < 0
1/(x^1) = -7/3 // * x^1
1 = -7/3*x^1 // : -7/3
-3/7 = x^1
x = -3/7
t_1 = 8/5
x^-1-8/5 = 0
1*x^-1 = 8/5 // : 1
x^-1 = 8/5
-1 < 0
1/(x^1) = 8/5 // * x^1
1 = 8/5*x^1 // : 8/5
5/8 = x^1
x = 5/8
x in { -3/7, 5/8 }
| 15x^2+11x=56 | | 10w^2-4w=0 | | 5z^2-14z-3=0 | | 4t+2=32 | | x+72=111 | | 20s^3-46s^2+35s-11s=0 | | 2x+14+x=4x+8 | | n(2)=9n-20 | | 6ln(3x-25)=30 | | (x-5)(50x^2+115x+63)=0 | | 2y^2+7y=7 | | 54p=8100 | | 14/8=x/52 | | 102=2(6+2x)+2x | | 100p=6300 | | 15y^2+y-6=0 | | -4(y+2)+2=2(y+6) | | 66p=4500 | | 7x^2-3x+6=0 | | 92p=16100 | | 1x-2=3x+2 | | 30t^2=-15t | | 5y^2=17x+12 | | 100p=1100 | | 6x-1=-90 | | x^2+8x=120 | | (5x+9)(3x^2+7x+2)=0 | | 19-10x=-12 | | 2(4/5x+3) | | 12.5=88 | | 100p=11000 | | 2x+x+6+2x=9+4x |