The equation R=30A-50 represents the revenue R (in dollars) you make by spending A dollars on advertising. Your revenue totaled $160. How much did you spend on advertising?

Which one is the correct answer, and why?

Frank has a devised a formula for his catering business that calculates the number of meatballs he needs to prepare. the formula is m=4a+2c, where c=number of children; m=number of meatballs; a=number of adults. how many meatballs are required for a party of 10 adults and 5 children?

If np3 /nc2 = 6, find the value of n