I am trying to help my daughter
and it has ben 27 years since i had algebra.
my questin is on solving equations and formulas.
If i could get a small refresher on how to do 
this i may can remember how to explain this to 
her. the problem is:

16z + 4x = y for x

If i could get a detailed walk through i can help her.

thank you.

                          16z + 4x = y

Get rid of all terms on the left which do not contain x
by adding their opposite to both sides.  We want to get 
rid of the 16z on the left so we will add -16z to both
sides. So put -16z under both sides.  Put the -16z under
the 16z.  On the right side put the -16z beyond the last
term because there is no term in z on the right side:

                          16z + 4x = y
                         -16z           -16z
                       -----------------------

Now add vertically term by term:

                          16z + 4x = y
                         -16z           -16z
                       -----------------------
                                4x = y - 15z

Now we get rid of the coefficient of x, which is 4, by
dividing both sides by 4:

                          16z + 4x = y
                         -16z           -16z
                       -----------------------
                                4x = y - 15z

                              4x       y - 15z
                             ----  =  ---------
                               4          4

Now we can cancel the 4's on the left,

                              1 
                              4x       y - 15z
                             ----  =  ---------
                               4          4
                               1 

                                        y - 15z
                                x  =   ---------
                                          4 

Edwin