If 3 times a number is 28 more than its opposite what is the number

n = 7

Step-by-step explanation:

Let n represent the number.  Then 3n = -n + 28, or 4n = 28.

Dividing both sides by 4 yields n = 7.

Check:  "3 times a number" is 3n = 21

The "opposite" of the number is -7.  

If we add 28 to this "opposite," we get 21.  This is correct:  21 = 21

a² + b²= c²

24² + 7² = c²

c= 25

-22

times both sides by 2, times () by 8, add alile terms, move terms, add alike and caculate divide both sides by 3