90 points a geologist studying an ancient riverbed calculates that there are at least 2,000 microfossils in every liter of soil that he collects.
how many liters of soil should he collect if he wants to obtain 7,500 microfossils for his research study? round your answer to the nearest tenth.
a. about 0.3 liters
b. about 2.7 liters
c. about 3.8 liters
d. about 37.5 liters

What is the ratio of the length of an object in yards to the length of the same object in miles?

(50 ) mrs. julien’s and mrs. castillejo’s classes are selling cookie dough for a school fundraiser. customers can buy packages of macadamia nut chip cookie dough and packages of triple chocolate cookie dough. mrs. julien’s class sold 25 packages of macadamia nut chip cookie dough and 30 packages of triple chocolate cookie dough for a total of $221.25. mrs. castillejo’s class sold 5 packages of macadamia nut chip cookie dough and 45 packages of triple chocolate cookie dough for a total of $191.25. (a) write the system of equations that model the problem. be sure to explain which equation represents which situation. (b) find the cost of each type of cookie. show your work. (c) explain which method you used to solve the system and why you chose that method.

Find the length of the radius of a circle with the center at -7+2i and a point in the circle at 33+11i