What is the length of qr rounded to the nearest whole number?

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

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

Does anyone know how to solve and graph this: 4 + | a + 2 | < 7the only part i don't get is the "4 +"