tom paid $1,166.40 for a new refrigerator, including $86.40 tax. What was the price of the refrigerator?

Fast phone couldn’t copy and paste so i decided to right it down

Someone me what is the area of this figure? 18m 18m 8m 16m

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.