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)
(5/7)*k+(1/3)*k+7 = 691/105 // - 691/105
(5/7)*k+(1/3)*k-(691/105)+7 = 0
(5/7)*k+(1/3)*k-691/105+7 = 0
22/21*k+44/105 = 0 // - 44/105
22/21*k = -44/105 // : 22/21
k = -44/105/22/21
k = -2/5
k = -2/5
| 3b+6+3/7b=330/7 | | n-5/7+4n=100/7 | | -19/4=d-6d-6 | | 2/7m+1/3+4m=-443/21 | | -3/4a-4/7+6a=559/308 | | -2/5+x+x=68/55 | | 3.2y=y+0.3+1.2 | | 4b-3/8+4b=-609/88 | | -134/7=-7x+2/7x+1 | | 1+2d-d=2 | | -106/7=-n-3n+6/7 | | -25/9=w+5w+2/9 | | -3y=21-7x | | 5/6b-5/9-1/2b=-29/9 | | 1+5a+1/3a=145/33 | | 6m+2-2/7m=454/7 | | 2/3=3n-5/6n-8 | | 19/3=-3t-t+5 | | -3/4+4/5m+1/4m=3/80 | | 3y=y+1.1+0.3 | | -674/315=4/7k+4k+2/5 | | 46/33=2k-2/5k+2/3 | | 3/4-2/3k+5/7k=59/84 | | 49/5=7a-1/5a+3 | | 2+1/2x+x=19/8 | | (1.3D)(0.7D)= | | 1-3/4x-2/7x=-15/14 | | -6+4/5w+3/7w=-2052/385 | | -763/10=3k+4k+7/10 | | 22/3=3a+1/3a+7 | | 62=2k+7k+8 | | 7-x-5x=25/2 |