Assume that 0< x < pi/2 and 0< y < pi/2. find the exact value of cos(x+y) if cos x = 3/5 and cos y = 4/5.

a. 25/24

b. -25/24

c. 24/25

d. -24/25

Lena reflected this figure across the x-axis. she writes the vertices of the image as a'(−2, 8), b'(−5, 6), c'(−8, 8), d'(−4, 2).

What is the value of m in the equation 1/2 m - 3/4n=16 when n=8

Aparticular telephone number is used to receive both voice calls and fax messages. suppose that 25% of the incoming calls involve fax messages, and consider a sample of 25 incoming calls. (a) what is the expected number of calls among the 25 that involve a fax message?