If it's not what You are looking for type in the equation solver your own equation and let us solve it.
t in (-oo:+oo)
(-5/7)*t+8 = 647/84 // - 647/84
(-5/7)*t-(647/84)+8 = 0
(-5/7)*t-647/84+8 = 0
25/84-5/7*t = 0 // - 25/84
-5/7*t = -25/84 // : -5/7
t = -25/84/(-5/7)
t = 5/12
t = 5/12
| 1/5d+9/10=16/15 | | 6k+2/5=332/5 | | x-6=-16/3 | | 5b+2/7=-23/7 | | 3/7n-1/3=-62/105 | | 2/3b+9=13 | | 1+7a=13/6 | | 1/2-3b=-11/2 | | -b+2=-6 | | -6a-5=-47 | | -2/3+4/7k=-46/105 | | 3/7b-3/5=-93/280 | | 2a+3/8=49/24 | | -1/2k-4/7=-27/35 | | -4/5+2/3n=-34/5 | | 2/5w+1/9=-71/495 | | -7x+2/5=-33/5 | | -1/5b+3=14/5 | | 3k+1=-20 | | -8/9+5w=532/9 | | 3/7+4t=227/7 | | -6a-2=-28/5 | | -1/6-5/6a=49/6 | | -8-2/7k=-632/77 | | -7t+6=-71 | | -6d-9=-5 | | 4/5m+1=41/5 | | 4/5n+2/5=38/5 | | 1/2d-2=-35/22 | | 4/5-7t=-136/5 | | 1/2t+8/9=79/18 | | -3/7k+5=65/7 |