I am not certain about this but if you follow PEMDAS and you keep in mind that your goal is to isolate the x than you get this answer:

ax+b/cx+d=2

Multiple each side by (cx+d).

ax+b=2(cx+d)

Distribute.

ax+b=2cx+2d

Subtract each side by b to get rid of it on the left side.

ax=2cx+2d-b

Then divide each side by a to get ride of it on the left side.

x=2cx+2d=b/a

I don't know for certain if that's correct or not, but it's my best guess. I hope it helps.