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)
-13 = c/(-7) // - c/(-7)
-(c/(-7))-13 = 0
1/7*c-13 = 0 // + 13
1/7*c = 13 // : 1/7
c = 13/1/7
c = 91
c = 91
| z-5z=8z-3-z | | 30=b*.6675 | | 3y^2=5y | | g-5=1 | | 3n-6=-24 | | (z-4z)=7z-(1-z) | | x-6/4=-3 | | 0,05*9+x=0,1(x+9) | | 7z-1-z=z-4z | | a=3.14r^2s/360 | | 5/4=x+3/4 | | 30=b*66.75 | | 2(c-5)=14 | | 2/3z=-12 | | -5(4x+2)+21x=14 | | 2(7n-8)+9n= | | 0,05*9+0x=0,1(x+9) | | x-6/6=-4 | | 8/z+3=7/z-9 | | 48-a^2=2a | | 8t+4q-12=x | | 6+6(r-1)=3+12r | | 2*22/7*7.5 | | 25n^2+10n-80=0 | | 17x=-3(2x+3)+7x | | 1-a=36 | | 2(6w+1)=4(w-5)-2 | | 42=5x-9+4x | | 6xy=29 | | 50n+75=65n | | 1/2+11x=1 | | 0,05*0x+0*9=0,1(x+9) |