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)
(1/7)*(k-6) = (3/7)*(k+6) // - (3/7)*(k+6)
(1/7)*(k-6)-((3/7)*(k+6)) = 0
(1/7)*(k-6)+(-3/7)*(k+6) = 0
1/7*(k-6)-3/7*(k+6) = 0
1/7*(k-6)-3/7*(k+6) = 0
-2/7*k-24/7 = 0
-2/7*k-24/7 = 0
-2/7*k-24/7 = 0 // + 24/7
-2/7*k = 24/7 // : -2/7
k = 24/7/(-2/7)
k = -12
k = -12
| -7+6(b-3)=-6b-13 | | 15=x/2 | | 16t^2-34t+15=0 | | 6=6k | | log(x)+log(x-11)=log(12x) | | b+5/4=12 | | 15f+2(2f+3)= | | -9(x-8)= | | -12+19=m-2 | | 92=2.3x | | x/-2+5=16 | | a/5-1=-9 | | 5/3+2/3x=37/15+7/5x+2/5 | | n+12.5=-5.8 | | 2x+15+x+20+3x-5=180 | | -2(b-9)=-24 | | -2(7x-4)+8x-1= | | 65+(h*20)= | | 5x+5=-19-7 | | 2314.50=(10*10x)27.50(17*30)750 | | -4=-3(-4) | | -19=z-4 | | v=(1/3)a*h | | 4.1=-10+x | | 2+2x+15=91 | | (x+3)=4(x-1) | | 4r+9r+5r-5= | | 4(y+1)=40-2y | | -4b-5+2b=x | | p-32=-35 | | 4(-3x+9)= | | 3(3-2x)+3=3x |