How do I solve this c + (-6c) + c + c

What set does not contain -3 the set of all real numbers the set of all integers the set of all whole numbers the set of all rational numbers

Barbara deposited $300 in the bank. if the bank pays her simple interest at the rate of 4 percent per year, how much money will she have in her account at the end of 9 months?

Find the area of an equilateral triangle with a side of 6 inches