John saves four times as mary. fred saves half as much as john. together, all three save $280 dollars. how much did each person save? let x = mary’s savings let = john’s savings let = fred’s savings

Which equation can be used to solve for the unknown number? seven less than a number is thirteen. n-7=13 7-n=13 n+7=13 n+13=7

Deepak plotted these points on the number line. point a: –0.3 point b: – 3 4 point c: – 11 4 point d: –0.7 which point did he plot incorrectly?

Ascientist places 24 cells in a petri dish. she knows the cells grow at an exponential rate, doubling in number every hour. how long will it take (in hours) for there to be 1100 cells in the dish? time to 1100 cells: 5.51832530 hours how long will it take to reach 110 cells? time to 110 cells : 2.1963972 hours what is the average rate of change in the number of cells between 9 hours and 11 hours? average rate of change: cells per hour what is the instantaneous rate of change after 7 hours? instantaneous rate of change: cells per hour note: you can earn partial credit on this problem.