If it's not what You are looking for type in the equation solver your own equation and let us solve it.
D( y )
y = 0
y = 0
y = 0
y in (-oo:0) U (0:+oo)
7/y-1 = -(1/y)-4-2 // + -(1/y)-4-2
7/y+1/y-1+2+4 = 0
8*y^-1 = -5 // : 8
y^-1 = -5/8
-1 < 0
1/(y^1) = -5/8 // * y^1
1 = -5/8*y^1 // : -5/8
-8/5 = y^1
y = -8/5
y = -8/5
| -y=4x+2 | | -4y^2-4y=0 | | 2y+8x=4 | | 3x+4x-7=22 | | (3,5)(3,8)= | | 0=4n+96-n^2 | | 37x-14+19=154 | | X/-3=18 | | -20-7n=-(-4-3n)-7n | | 10x+30=5x+15 | | 3x^3-21x^2+24x-27=0 | | 3x+10=4x+12 | | 5x-9=3(-3) | | 2x+x+7=8 | | 3(x-4)=-6 | | 1+8b+6=10(6)-5 | | 2x-3=6x+13 | | 3x-5+7+2x=12 | | X^2-2/3x-26/9=0 | | 3a-1.15=-5.525 | | 5k+6k=-2+2k+9 | | -1/4*2/3 | | -1/4x2/3 | | 2c^3+3c^2-8c-12=0 | | -18x+2y=20 | | 5y-1-3y=51/5 | | 12x^2=8x+15 | | -3x+1=-23+3x | | 2x-(-4)=6 | | 1/7+3/4 | | 15/16-3/8 | | 4x+2=3x+12 |