Naman purchases 3 vases for an upcoming event for m dollars each. each vase is charged an addition 5% sales tax. which expressions can naman use to express the total cost of the 3 vases? select each correct answer. 1.3.05m 2.3(m+0.05m) 3.3.15m 4.3m + 0.05m

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.