Brazil has an area of approximately 8.51 x 10^6 square kilometers and a population of about 1.99 x 10^8 people. Portugal has an area of
approximately 9.21 x 10^4 square kilometers and a population of about
1.08 x 10^7 people. On average, which country has a greater number of
people per square kilometer? Explain how you know.

Acircular hot tub located near the middle of a rectangular patio has a diameter of 48 inches. the patio measures 11 feet by 6 feet. what is the area of the patio that is not covered by the hot tub?

Pls! does anybody know a shortcut for answering these types of questions in the future?

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.