(6 + 8) (3 - 2) = help plz

Aquantity with an initial value of 3900 decays exponentially at a rate of 35% every hour. what is the value of the quantity after 0.5 days, to the nearest hundredth?

The three sides of a triangle have lengths of 4x+3, 2x+8, and 3x-10. what is the length of the shortest side if the perimeter of the triangle is 136cm?

Abank manager wants to encourage new customers to open accounts with principals of at least $2,500. he decides to make a poster advertising a simple interest rate of 3%. what must the principal be if the bank manager also wants to advertise that one can earn $10 the first month? can the poster correctly say, "open an account of $2 comma 500 and earn at least $10 interest in 1 month! "?