If it's not what You are looking for type in the equation solver your own equation and let us solve it.
x in (-oo:+oo)
x+2/3 = 5/21 // - 5/21
x+2/3-(5/21) = 0
x+2/3-5/21 = 0
x+3/7 = 0 // - 3/7
x = -3/7
x = -3/7
| 6/35=d+3/5 | | k-10=-21 | | t+2/3=-7/3 | | d/4=-3 | | 3/4+w=29/28 | | 19/10=t+1 | | a/6=-2/7 | | 6+k=7 | | -1/24=d-7/8 | | k-5/7=9/7 | | 4/5=m+1 | | -7=k-8 | | w+7=11 | | w/2=-5/6 | | 47/60=x+1/5 | | m+5/8=13/8 | | 6d=-18 | | x=1/8 | | -13/3=m-1/3 | | b+3/5=38/5 | | n/-6=-4/5 | | k/2=4/7 | | k+6=9 | | 1/4+a=-21/44 | | t+5=6 | | 2/5+m=11/40 | | d-2=8 | | -5/9+n=31/9 | | d-3/5=-18/5 | | 5/9=w+5/9 | | n+1/4=9/4 | | -3/8+t=-1/24 |