For i = -1, what is the sum (7 + 3i) + (-8 +91) ? A) - 1 + 121
B) - 1 - 6
C) 15 + 121
D) 15 – 6

Two customers went to a post office. first customer paid $12 for 14 and 5 envelopes the second paid 24.80 for 10 postcards and 15 envelopes. what is cost of each envelope?

For a science project, a high school research team conducted a survey of local air temperatures. based on the results of the survey, the found that the average temperatures were around 10 degrees higher than expected. this result was wrong. the trouble with the survey was that most of the locations were exposed to direct sunlight and located over asphalt or sand, which resulted in higher temperatures than normal. this is a classic example of an error in which phase of inferential statistics?

Find the circumference of a pizza with a diameter of 10 inches round to the nearest tenth