(! ) two cooks purchased plates and cups at the same store. the first cook bought 4 plates and 5 cups for a total of $25.25. the second cook bought 7 plates and 3 cups for a total of $25.50.
what is the price of a plate?

Apatient is to take 60 mg of an antibiotic on day 1, take 45mg on days 2 and 3, take 30mg on days 4 and 5 and take 15 mg on days 6 and 7. how many total mg will the patient take?

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?

Determine which expressions represent real numbers and which expressions represent complex number. asaaap! plis!