The general function P(t) = 640ekt is used to model a dying bird population, where P0 = 640 is the initial population and t is time measured in days. Suppose the bird population was reduced to one quarter of its initial size after 9 days. How long will it take before there are only 40 birds left in the population? Simplify your answer as much as possible.

Marco is studying a type of mold that grows at a fast rate. he created the function f(x) = 345(1.30)x to model the number of mold spores per week. what does the 1.30 represent? how many mold spores are there after 4 weeks? round your answer to the nearest whole number. 1.30 represents the number of mold spores marco had at the beginning of the study; 985 mold spores 1.30 represents the number of mold spores grown in a given week; 448 mold spores 1.30 represents the 30% rate of weekly growth; 345 mold spores 1.30 represents the 30% rate of weekly growth; 985 mold spores

Factor -8x3-2x2-12x-3 by grouping what is the resulting expression?

When you answer this can you explain