Answer:

Step-by-step explanation:
The given number is 
We need to write this number in standard form.
Any no is given in the standard form is given by :

Where
a and b is real no and integer
It means,

Hence, this is the required solution.
Answer:
Total 390 hardcover books were sold
Step-by-step explanation:
Complete question
The author received a total of $195,000 for the book sales. How many hardcover books were sold if the cost of one hardcover book is $500. Type in numbers only.
Solution
Given-
Total value of sale of hard cover = $195,000
Cost of one hardcover book = $500
Number of books sold = Total value of sale of hard cover/Cost of one hardcover book
Number of books sold = $195,000/$500
Number of books sold = 390
Total 390 hardcover books were sold.
Only 20%of earths water is useable
Let the cost of the shirt be y and the price by the which the shirt is sold is 2y. This means that at 15% discount, the shirt is sold at 1.7 of its original cost.
Answer:
1300
Step-by-step explanation:
Let the amount put in the station's tank = x
4(400 + x) = 8100 - x Remove the brackets
1600 + 4x = 8100 - x Subtract 1600 from both sides
1600 - 1600 + 4x = 8100 - 1600 - x Do the subtraction
4x = 6500 - x Add x to both sides
4x + x = 6500 - x + x
5x = 6500 Divide by 5
5x/5 = 6500/5
x = 1300
1300 gallons were added to the station's tank.