Mrs sevi bought 12 mangoes and apples. Each mango cost $2.40. Each apple cost $0.60. The total cost of the mangoes is$7.80 more than the total cost of apples. How many mangoes did mrs sevi buy?

15 point ! ~ see if you know the answer to both you!

Asocial networking site currently has 400,000 active members, and that figure is predicted to increase by 32% each year. the following expression represents the number of active members on the site after t years.

What is the answer to this question? i'm a bit stumped. also how do i do it? 5(x - 4) = 2(x + 5)