P=200-Q C=Q3-4Q2-40Q+1500
Q là sản lượng, P là đơn giá
a/ Hãy xác định mức sản lượng và giá bán để tối đa hóa lợi nhuận
b/ Tính và nêu ý nghĩa của hệ số co giãn của hàm cầu theo giá và sản lượng tối ưu

Lance lived in portugal and brazil for a total of 14 months to learn portuguese. he learned an average of 130 new words per month when he lived in portugal, and an average of 150 new words per month when he lived in brazil. in total he learned 1920 new words. write a system of equations to represent the situation. use x to represent portugal, and y to represent brazil

Given abc find the values of x and y. in your final answer, include all of your calculations.

Kevin has a spinner that has 10 equal sections and 2 sections of each color—red, blue, green, yellow, and purple. kevin spins the spinner 180 times. kevin determines about how many times the spinner will land on red or green, and his work is shown below. -kevin has the formula reversed; it should be the total number of sections over the number of red or green sections. -kevin should have used a 4 in the numerator because there are 2 red sections and 2 green sections. -kevin should multiply by the number of sections in the spinner rather than the total number of spins. -kevin calculated the prediction correctly and did not make any mistakes.