Need help hurry it’s due soon it’s a test anyone good at math please ?

What is the missing constant term in the perfect square that starts with x^2 -20x

In the diagram, the ratio of ab to ae is (1/2) . what is the ratio of the length of to the length of ?

Acolony contains 1500 bacteria. the population increases at a rate of 115% each hour. if x represents the number of hours elapsed, which function represents the scenario? f(x) = 1500(1.15)" f(x) = 1500(115) f(x) = 1500(2.15) f(x) = 1500(215)