2. a) 7^12/7^4 = 7^8
b)x^11/x^5 = x^6
c)12x^5/3x^2 = 4x^3
d)7x^6y^3/14x^3y = .5x^3y^2
5. a) (2x)^3(3x^2)^4 = 648x^11
b)(5x)^7/(5x)^4 = 25x^2
c)(2x)^5/-8x^3 = -4x^2
d)(4x^2y^5)(-3xy^3)^3 = -12xy^4
6. How long does it take light to travel from the Sun to Earth? Answer to the nearest minute.(scientific notation)
Distance: 1.5x10^11 m
Speed: 3x10^8 m/s
1.5x10^11/3x10^8 = 500 sec.
500/60 ~ 8 minutes.
7. a) In 2004, the pop. of Mexico was about 1x10^8. Mexico has a land area of about 7.6x10^5 square miles. What was the pop. density?
1x10^8/7.6x10^8 =132(rounded)
b) In 2004, the pop. of Japan was about 1.3x10^8. Japan has a land area of about 1.5x10^5 square miles. What was the pop. density?
1.3x10^8/1.5x10^5 =867(rounded)
c)How did the pop. densities of Mexico and Japan compare in 2004?
Though the area of land was significantly greater in Mexico, the pop. density is less, because it is spread out more than Japan's low-area, high-population set-up.
Am I clear? --thanks!