Respuesta :

Answer:

Step-by-step explanation:

20 = 8x + 4r can be rewritten in multiple ways.

1.  Reduce the coefficients:  5 = 2x + r

or

2.  Solve for r:  r = 5 - 2x

or

                                 5 - r

3.  Solve for x:  x = -----------

                                    2