15. the operation * is defined on the set r
a
+b
– 1 for
of real numbers by a*b =
all a, ber.
(a) is r closed under* ?
(b) is the operation * commutative
in r?
(c) is the operation * associative in
r?

True or false? a circle could be circumscribed about the quadrilateral below.

Which of the following is a solution of z^6 = 64i? 2(cos105° + isin105°) 2(cos120° + isin120°) 2(cos135° + isin135°) 8(cos15° + isin15°)

50 people men and women were asked if they watched at least one sport on tv. 20 of the people surveyed are women, but only 9 of them watch at least one sport on tv. 16 of the men watch at least one sport on tv. make a a two-way table and a relative frequency table to represent the data.