Remark
You cannot give an answer to this unless you are give the fastest speed of a swimmer. That stat is not an easy one to decide upon. At what distance for example or do you eliminate distance? Since this is a college level question, I don't think it unreasonable that you have to research raw distance over fastest time.
The fastest speed I can find is 100 meters in 46.91 seconds. That means that the actual speed of the swimmer is 100 meters / 46.91 = 2.132 meters / second.
Givens
Set up a proportion with the numbers found and given
Speed of ball / speed of swimmer = 21.12 / 1
Speed of ball = x
Solution
Speed of swimmer = 2.132 m/s
x / 2.132 = 21.12 / 1 Multiply Both sides by 2.132
x = 21.12 * 2.132 / 1
x = 45.02 m/s
Answer
45.02 m/s
No this number is not written in scientific notation
In scientific notation, it'll look like
4.8 * 10 ^14
In scientific notation it's 10 ^ n
NOT 100^n
Hope this helps
Solution
- The solution steps are given below:

Final Answer
y = 13.14%
The screenshots of the solution are:
It's 6/35 because of means multiply and take numerator times numerator and denominator times denominator when you multiply fractions. 2 x 3 = 6 over 5 x 7 = 35. 6/35.
(2x + 1)^2 - 2(2x^2 - 1) = 4x^2 + 4x + 1 - 4x^2 + 2 = 4x + 3