Xét tính đơn điệu hàm số y=1+4x-x^2

Tickets to a science exposition cost $5.75 each for studentd and $7.00 for adults.how many students and adults went if the ticket charge was $42.75

Compute the standard deviation of the following set of data to the nearest whole number. 10, 10, 15, 20, 25

Find the center of the circle that can be circumscribed about efg with e(4,4) f(4,2) g(8,2)