Please help I am not sure on this one!

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?

What are the values of a, b, and c in the quadratic equation 0 = x2 – 3x - 2? a = 1, b = 3, c = 2 a=, b = -3,c=-2 a = 1, b = 3, c= 2 a = 1.0= -3, c = 2

Ana earns 2.5% simple interest on $2,000 in her savings account. she does not make any deposits or withdrawals. after 3 years, how much interest will ana have earned on her savings account?