If it's not what You are looking for type in the equation solver your own equation and let us solve it.
a in (-oo:+oo)
a+a+7 = 7 // - 7
a+a-7+7 = 0
2*a = 0 // : 2
a = 0
a = 0
| 9+7x+6x=-4 | | 9=6x+4x+9 | | 2-7w+6w=-7 | | -125=-7k-3k-5 | | -3-4a-6a=-53 | | 3-2t-2t=-9 | | 116=7a+7a+4 | | 4x-1+5x=-1 | | 1+2x+4x=55 | | 2=-5x+4x-3 | | 8-3m-5m=48 | | -31=2w+2w+9 | | a-10+4a=-60 | | 2+7b+2b=-7 | | 7t-5+4t=-137 | | 7+2n-3n=12 | | 1200-24x=500 | | -105=-4n-7n+5 | | -5+w+2w=-35 | | 4=3n+6n+4 | | 6b-2+7b=-93 | | -2k-5+7k=-35 | | 4+7m+5m=76 | | 5d+1-3d=23 | | 7w+7+5w=55 | | 5=-4m-5m+5 | | 7-x-x=1 | | 8+4x-3x=5 | | 8-2b+4b=28 | | 2+x+7x=-70 | | 83=3n+5n-5 | | -4m-5-6m=-5 |