If it's not what You are looking for type in the equation solver your own equation and let us solve it.
D( r )
r = 0
r = 0
r = 0
r in (-oo:0) U (0:+oo)
4/6 = 6/r // - 6/r
4/6-(6/r) = 0
4/6-6*r^-1 = 0
-6*r^-1 = -2/3 // : -6
r^-1 = 1/9
-1 < 0
1/(r^1) = 1/9 // * r^1
1 = 1/9*r^1 // : 1/9
9 = r^1
r = 9
r = 9
| 7(2x+3)-4(2x+1)=2(x+1) | | -2+7m=8m-8 | | F(x)=500/x | | -4d=-5d-7 | | -7(1+3a)=-24 | | -x^2+0x-1=0 | | 2m+10=4m-4 | | ln(5x+18)+ln(3)=2*ln(x) | | -7+j=-2j+8 | | x(-13x^2+130x-200)= | | -6/-18 | | (4a-12)+3a=6a+1 | | -0.75x+9-1.25x-2=1 | | 10-4y=-5y | | 22=40-6x | | -13x^3+130x^2-200x= | | -9(3k+7)=15 | | 5+3(q-4)=2(q+2) | | 9+2p-6=9p+13-5p | | 73+x+46+x+71=180 | | X^2+X+1=36 | | 6x=-8y-2 | | 5=h/2.2 | | y=96+0.6x | | c=wtc/1000 | | 16=70-2q | | 3(x+6)=6-5(x+1) | | 1(7/8y)=4(1/2) | | 3x+18=11(x+1) | | 3/4|8t-12|=6(t-1) | | 2=-0.375x-9-0.125x | | -9(3-5c)=-27 |