Twenty billion is how much than nine billion, write the answer in scientific notation

Tim's electricity costs 4.3 ¢ a kilowatt hour or 100 watts. How much will it cost to run the following appliances for 10 hours? (round to the nearest cent) a Dryer @ 4,000 watts. Cost = a Heater @ 1,500 watts. Cost = a Radio @ 40 watts. Cost =

Problem page debra finished her chemistry assignment in 15 hours. then she completed her history assignment in 34 hours. what was the total amount of time debra spent doing these two assignments?

Explain how place value could be used to find the difference between 4.23 into 2.75

1,374 times 6 estimate

Carl wants to plan a garden that is 1 1/2 yards long with an area of 3 1/2 square yards. width of the garden should be

What number multiplied by (-7) = 42

What are three types of irrational numbers?

What is the number that has the same absolute value as 81

Write the principal square root of the integers between 320 325. Which of these is a rational?

Suppose Johnny invests $2,745 into an account, which has been earning interest for many years and he now has a total of $39,974.