Which of the following math statements contain variable(s)? check all that
apply.
a. 9-1 = 8
b. 9-1 = x
c. 9- — = 8
d. x-_=8

Find the pattern and use it to list the nth term in the sequence. 6, 12, 20, 30, 42, 56, the nth term of the sequence is

Are the corresponding angles congruent? explain why or why not.

Monitors manufactured by tsi electronics have life spans that have a normal distribution with a standard deviation of 1800 hours and a mean life span of 20,000 hours. if a monitor is selected at random, find the probability that the life span of the monitor will be more than 17,659 hours. round your answer to four decimal places.