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)
240/y = 12 // - 12
240/y-12 = 0
240*y^-1 = 12 // : 240
y^-1 = 1/20
-1 < 0
1/(y^1) = 1/20 // * y^1
1 = 1/20*y^1 // : 1/20
20 = y^1
y = 20
y = 20
| x*2*8=168 | | x*2*7=168 | | x/80=6 | | x*2*14=168 | | x*2*y=168 | | 284=39-W | | 8x+4=12x-4 | | x/-2=-7-(-10) | | -3+6+5x=7x-8x | | -3(x+11)+259=31+30 | | -16t^2-100t+100000=0 | | (3/2)x-(5/6)+x=(1/2)x+(2/3) | | y=10(3u+1)(1-5u) | | f(-1)=3y^2+7y-2 | | -7x-10y=70 | | 5(3+x)-(8x+9)=-4x | | -6w+5=7(w-3) | | -3(v+2)=2v+24 | | 5v-12=78 | | 5y-9y= | | 2+z=4.5 | | 4X^2+4X+89=0 | | 3-2t=-9 | | 7(x+5)+5(2x+1)= | | -8u-24=7(u+3) | | s-s=s+4 | | x+3.6=-4.75 | | 2(2x-1)= | | 9-2=8-s | | 9-s=s-s | | 9-7s=4s-3s | | 4s=9s-2 |