Question

What is ax-b=c for x

Answer 1

Isolate x ( leave x alone ) 

So you first subtract b and put it to the other side. 

ax = c-b 

Then divide both sides by a. 

x = c-b / a

Answer 2

Do the order of operations backwards. so SAMDEB
subtraction -->  -b
add b to both sides.
so now it's ax= c+b
there is no addition
multiplication --> (A)x(X), divide by A
Now it's x= (c+b)/a