If it's not what You are looking for type in the equation solver your own equation and let us solve it.
D( c )
c = 0
c = 0
c = 0
c in (-oo:0) U (0:+oo)
3/c = 8/28 // - 8/28
3/c-(8/28) = 0
3/c-2/7 = 0
3*c^-1 = 2/7 // : 3
c^-1 = 2/21
-1 < 0
1/(c^1) = 2/21 // * c^1
1 = 2/21*c^1 // : 2/21
21/2 = c^1
c = 21/2
c = 21/2
| 17*3/22 | | 3(3k+5)=9k+4 | | 2p+5=9p-30 | | 6(-v-3)+8v=-6+5v | | 5(c+3)-2c+9=2(c-1)+13 | | N^3=257 | | 2x-5x+6=-15 | | -8=t | | 12r=7(3r-5s)-9(6r+3s)-2s | | 8.75*2+6.50*3=.50x | | (4x-7)-(8x-37)-64=180 | | 7=-3c+2 | | 7.50+15b=75 | | 6/10=w/15 | | X-7/2=22 | | ax+7b=4x-6 | | -5+14=-11 | | (8x+9)2=4 | | -24/3=3r/3 | | 63-10x=19+12x | | 9x^2-300=-141 | | -2x-16-5x=-3x+11 | | -18n+12=-14n-4 | | 48=8x-5 | | (3x-4)-8=18 | | -6x-17/5=11 | | 2x+3y+7=180 | | x=.2x+.25x+220-110 | | 96m+2=80m+3 | | X-7/9=11/9 | | -14+-22= | | 30+6x=48.90 |