22. If you add a number to a series of data, and it doesn't change the mean, that number MUST equal the mean. Try adding the mean number into it, hopefully it doesn't change the mode or median either.
23. Basically I think (can't quite read all the question!) just work out the circumference of a circle with radius 20 feet (urgh imperial), ie 2*pi*r so 40pi.
The answer is x = 9/13
Hope in helped
To find equivalent numbers you multiply the top and bottom by the same number. Examples are: 2/10 (by 2), 3/15 (by 3), 4/20 (by 4), etc.
1 * 9 = 9
------------
5 * 9 = 45
So another is 9/45
hope it helps!
(x + 1) x (x - 4). When you check it you will get your original expression.
