The answer is c=ab-d/a
Step 1) Find which variable you are asked to solve for (in this case, C)
Step 2) Find what’s happening to that variable (in this case, B is being subtracted by C and a is being multiplied to b-c.
Step 3) Use properties of equality to undo operations in order to isolate the variable. You begin by undoing b because when doing inverse operations, you perform the order of operations (PEMDAS) backwards.