Please help dont answer if u dont know the answer

Find the domain of the following expression: 1/(√x)-2

Angles r and s are complementary. the measure of angle r is 31 degrees. which equation can be used to find angle s?

Atest consists of 10 multiple choice questions, each with 5 possible answers, one of which is correct. to pass the test a student must get 60% or better on the test. if a student randomly guesses, what is the probability that the student will pass the test?