Find the sum and express it in simplest form. (-3t^3-5t)+(7t^3+4t-4)

Country carpets charges $22 per square yard for carpeting, and an additional installation fee of $100. city carpets charges $25 per square yard for the same carpeting, and an additional installation fee of $70

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)