If tan x=8/15, and 0° < x < 90°, find cos(x/2).

Which of the following expressions are equivalent ?

Abox contains 1 plain pencil and 4 pens. a second box contains 5 color pencils and 5 crayons. one item from each box is chosen at random. what is the probability that a plain pencil from the first box and a color pencil from the second box are selected? write your answer as a fraction in simplest form.

In parallelogram abcd the ratio of ab to bcis 5: 3. if the perimeter of abcd is 32 find ab