Which of the following best explains why cosine 2 pi/3 is not equal to cosine 5 pi/3

In the given triangle, ∠aed ∼ ∠ abc, ad = 6.9, ae = 7.2, de = 5.2, and bc = 10.2. find the measure of bd and ce. round your answer to the nearest tenth.

This is a rational expression because the denominator contains a variable. this is a polynomial with 3 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 4 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 4 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 3 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 5 terms.

For the chance to be team captain, the numbers 1-30 are put in a hat and you get two chances to pick a number, without replacement. which formula correctly shows how to find the probability that you choose the number 1 and then 2?