Respuesta :

Answer:

Step-by-step explanation:

I will assume that you meant:  (-3/7)(y-28) - (1/21)y

Using the distributive property of multiplication, we get:

(-3/7)y + (3/7)(28) - (1/21)y

Let's first reudce the middle term.  We get:  12

Then we have:

(-3/7)y + 12 - (1/21)y

Here there are two different denominators.  We must combine the y terms.  The LCD here is 21.  Multiplying (-3/7)y by 21/21, we get the equivalent:

-9y

------ + 12 - (1/21)y

 21

or:

-9y          21

------ + 12----- - (1/21)y

 21           21

Combining the y terms, we get (-10/21)y:

-10y      252

------- + -------- = (1/21)(-10y + 252)

 21          21