Manuela makes $21 in commissions over the first three hours that she worked selling magazines. how many dollars must she make during the fourth hour to average $8 an hour for the full four hours

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

Tom can paint the fence in 12 hours, but if he works together with a friend they can finish the job in 8 hours. how long would it take for his friend to paint this fence alone?

Identify the expression equivalent to 4(x + x + 7) − 2x + 8 − 4 by substituting x = 1 and x = 2.