Please help its for a test

Factor x2 – 8x + 15. which pair of numbers has a product of ac and a sum of what is the factored form of the

Given the equation f(x)=a(b)x where the initial value is 40 and the growth rate is 20% what is f(4)

Campus rentals rents 2 and 3 bedrooms apartments for $700 ans $900 a month respectively. last month they had six vacant apartments and reported $4600 in lost rent. how many of each type of apartment were vacant?