Question

The value of y varies directly with x. If x = 15, then y = 12. What is the value of y, when x = 21?

Answer 1

Answer: 16.8

Step-by-step explanation: if x= 15 and y =12 we know that y =.8 of x or 4/5 of x.  Knowing this we can divide x (21) by 5 and get 4.2.  We can then multiply this and get 16.8 which is 4/5 of x(21).  y=16.8