If it's not what You are looking for type in the equation solver your own equation and let us solve it.
k in (-oo:+oo)
7*k+4 = 88 // - 88
7*k-88+4 = 0
7*k-84 = 0 // + 84
7*k = 84 // : 7
k = 84/7
k = 12
k = 12
| 1/5k-10=-248/25 | | 6m+1=61 | | -1/3t-10=-154/15 | | 2/5+4b=22/5 | | 4/5t+2/9=-134/45 | | -2/3m-1=-17/27 | | 8+5w=18 | | 1/6+1/3m=-19/6 | | -5x+3/10=-69/20 | | 5t+2/3=-178/3 | | -3/7d+3/7=30/49 | | -n+6=18 | | 1+1/4x=1/4 | | 5/7w+4=89/21 | | t-2/5=0 | | -1+1/2t=-5/6 | | 7d-7/8=-147/40 | | 1/3n-9=-10 | | 2/3d-2/5=64/15 | | 1+4/7m=19/7 | | -3/8-3k=-99/8 | | 3/4b+7/9=73/198 | | -2/3t-1/2=-1/2 | | -6m+10=-56 | | 1/9+2/3w=23/99 | | 2/3-b=-28/3 | | 5/7a-3/4=19/28 | | 1/2t+7=29/4 | | 5x+9=144/11 | | -1+3/4d=-7 | | 1/2a-3/4=-11/16 | | 8/9+5/6w=37/36 |