The following two-way table describes student's after school activities. Find the probability that a
randomly selected student either does sports or
works.
Grade
Sports
Music/Drama
Work
Sophomore
20
7
3
Junior
20
13
2
25
5
Senior
5
P(Sports U Work) = [?]
Round to the nearest hundredth.

Prove (a) cosh2(x) − sinh2(x) = 1 and (b) 1 − tanh 2(x) = sech 2(x). solution (a) cosh2(x) − sinh2(x) = ex + e−x 2 2 − 2 = e2x + 2 + e−2x 4 − = 4 = . (b) we start with the identity proved in part (a): cosh2(x) − sinh2(x) = 1. if we divide both sides by cosh2(x), we get 1 − sinh2(x) cosh2(x) = 1 or 1 − tanh 2(x) = .

Can someone factor this fully? my friend and i have two different answers and i would like to know if either of them is right. you in advance. a^2 - b^2 + 25 + 10a

Acd that is originally priced at $15.85 red-tagged for the sale. what is the sale price of the cd