Using logarithms property of log(x)+log(y)=log(xy)
so here, you can sum the equation to;

so you can simply say that;

and by multiplying (x+6)*(x-6)

and as you know also that;

is same as

so you can simply state it as;

And you can check your work by substituting with 10 instead of x in the original function.
Hope this helps!
6x=7-4y
Move 'y' to one side
6x-7=-4y
6x-7
------- = y
-4
About 6 times. 6.4 to be exact!