Help please!! If y varies directly with x, and x = 7 when y= 28, find y when x = 13.

1. y= 4
2. y=17
3. y= 42
4. y = 52

An an average person has 6×10 by the power of two as many red blood cells as white blood cells a small sample of the blood has 7×10 by the power of three white blood cells about how many red blood cells are in the sample

What is the prime factorization of 23 ?me with this question

How can you tell when x and y are not directly proportional?