If it's not what You are looking for type in the equation solver your own equation and let us solve it.
n in (-oo:+oo)
n/(-7) = 4/5 // - 4/5
n/(-7)-(4/5) = 0
n/(-7)-4/5 = 0
-1/7*n-4/5 = 0 // + 4/5
-1/7*n = 4/5 // : -1/7
n = 4/5/(-1/7)
n = -28/5
n = -28/5
| t+2/3=4/15 | | d/-2=-1 | | t-7/10=53/10 | | -6k=-10/3 | | b+5/6=7/6 | | 13=m+8 | | d-1=8 | | x+2=7/3 | | 6x=-16/3 | | d-2/3=-1/24 | | k+5=62/11 | | 59/88=d+1/8 | | 1/2k=1/11 | | k+5/8=9/8 | | 2/3+k=-1/3 | | 3+t=23/8 | | w+2=8/3 | | -1/3a=-1/6 | | d-4/5=6/5 | | m+1=7/4 | | w-4=-9/2 | | d+1/7=8/7 | | b-3/5=47/5 | | t+3/5=6/5 | | 62/11=w+5 | | m-1=-8/9 | | b/-7=-3/7 | | k/4=-4/7 | | X+-9=21 | | -1+t=-21/11 | | m-3/4=0 | | b+2=5/2 |