Convert (4,3π\2) to rectangular form

What is the percent of increase for a population that changed from 438,000 to 561,000

Offering 30 if a plus b plus c equals 68 and ab plus bc plus ca equals 1121, where a, b, and c are all prime numbers, find the value of abc. the answer is 1978 but i need an explanation on how to get that.

What is 100,000 times 1/100,000, using the standard method of multiplication? write the answer as 10 to a power.