Help due soon plz help

Bob’s bank charges him a $3.15 service fee every time he uses an out-of-network atm. if bob uses an out-of-network atm an average of three times every two weeks, how much will he pay in service fees over the course of a year? a. $327.60 b. $109.20 c. $491.40 d. $245.70 select the best answer from the choices provided a b c d

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.

Write the factored form of this trinomial 9x^2+18x-7