What is the product of the complex numbers 3 - 4iand 6+i where i= -1

Element x decays radioactively with a half life of 8 minutes. if there are 450 grams of element x, how long, to the nearest tenth of a minute, would it take the element to decay to 37 grams?

Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?

In a two-digit number the units' digit is 7 more than the tens' digit. the number with digits reversed is three times as large as the sum of the original number and the two digits. find the number.