Kelly had to multiply 5, 173, and 20. instead of multiplying the result of 5 of 173 by 20, she recognized that it would be easier to multiply 5 times 20 to get 100, and then multiply 100 times 173 to get 17,300. what property did kelly apply please help its for algebra 1 and 2 and i have no clue ​

Rachel reads 1/5 of the pages of a book plus 12 pages on the first day. on the second day, she reads 1/4 of the remaining pages plus 15 pages. on the third day, she reads 1/3 of the remaining pages plus 18 pages. on the fourth day, she reads the remaining 70 pages. how many total pages are in the book?

The average number of vehicles waiting in line to enter a parking lot can be modeled by the function f left parenthesis x right x squared over 2 left parenthesis 1 minus x right parenthesis endfraction , where x is a number between 0 and 1 known as the traffic intensity. find the rate of change of the number of vehicles waiting with respect to the traffic intensity for the intensities (a) xequals0.3 and (b) xequals0.6.

What are the solutions of the system? solve by graphing. y = x^2 + 3x + 2 y = 2x + 2