Answer:
29
Step-by-step explanation:
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
(4x - 4) - 3 simplified = 4x -7
I would if i had paper:( its hard to explain
So, this question is basically asking us "If we had an x instead of a 2, would this be true?" We can try and see what we get:
So, if we want to show this we have to change the numerator or denominator in such a way that we can cancel some common factors. Notice that 
If we replace the factored numerator with the original one, we get:
Since we have an equality, this relation is proved.
