If it's not what You are looking for type in the equation solver your own equation and let us solve it.
c in (-oo:+oo)
(-1/7)*c = 21 // - 21
(-1/7)*c-21 = 0
-1/7*c-21 = 0 // + 21
-1/7*c = 21 // : -1/7
c = 21/(-1/7)
c = -147
c = -147
| D/2+6=18 | | 4/5=x/7.5 | | 3t=6 | | 9-.4a=2.1 | | 3x-5+7=14 | | =-3-8(-5a-1) | | 3(2x+1)+x= | | (3x-7)/(x^2-5x+6) | | t-3=6 | | a^2+2a-24= | | y-15.25=10.05 | | 3x+10y=10 | | 770=2(4x+35)+2x | | =9a-4(2a+5) | | x=71-1.5y | | 4-9x=6-13 | | X/5+2/5=4 | | t^2+8t+15= | | 14/a=6.8 | | =8-3(6-6x) | | a/14=6.8 | | 1/2(10-9x)=3/2 | | 8x+40=2(x-7) | | =5x-7(2-4x) | | 2-12e=7e+8 | | n(4)=6(6) | | a^14=6.8 | | 20=x/5 | | 8+4w=12 | | 2x-2=6x+38 | | 2(71-1.5x)+3x+38=180 | | n(4)=6(4) |