Activity 3.4.4. consider the region in the x-y plane that is bounded by the x-axis and the function f (x) 25 − x 2 . construct a rectangle whose base lies on the x-axis and is centered at the origin, and whose sides extend vertically until they intersect the curve y 25 − x 2 . which such rectangle has the maximum possible area? which such rectangle has the greatest perimeter? which has the greatest combined perimeter and area? (challenge: answer the same questions in terms of positive parameters a and b for the function f (x) b − ax2 .)

Aprisoner is trapped in a cell containing three doors. the first door leads to a tunnel that returns him to his cell after two days of travel. the second leads to a tunnel that returns him to his cell after three days of travel. the third door leads immediately to freedom. (a) assuming that the prisoner will always select doors 1, 2 and 3 with probabili- ties 0.5,0.3,0.2 (respectively), what is the expected number of days until he reaches freedom? (b) assuming that the prisoner is always equally likely to choose among those doors that he has not used, what is the expected number of days until he reaches freedom? (in this version, if the prisoner initially tries door 1, for example, then when he returns to the cell, he will now select only from doors 2 and 3.) (c) for parts (a) and (b), find the variance of the number of days until the prisoner reaches freedom. hint for part (b): define ni to be the number of additional days the prisoner spends after initially choosing door i and returning to his cell.

The balance of susu's savings account can be represented by the variable b. the inequality describing her balance b > $30 . which could be a solution to the inequality?

Question 1 (3 points) saved what is the solution for the following system of equations? use any method to solve. y = -x +4 y = x - 2 question 1 options: ( 4 , -2) (2, 1) (3, 1) (3, -2) question 2 (3 points) saved the solution to a system of equations is where the lines intersect. question 2 options: true false question 3 (3 points) which ordered pair is the best estimate for the solution of the system of equations? the graph of the system of equations : y = 3/2x +6 and y=1/4x - 2 question 3 options: (-6, -3) (-6.5, -3.5) (-7, -4) (-7, -3.5) question 4 (3 points) what is the solution for the following system of equations? use any method to solve. 2x + 8y = 4 x = -3y + 5 question 4 options: x = 14, y= -3 x = 2, y = -3 x = -3, y = -3 x = 12, y = 5 question 5 (3 points) solve the following system using any method. 8a - 4b = 20 5a - 8b = 62 question 5 options: a = 5, b = -4 a = 8, b = 4 a = -5, b = -8 a = -2, b = -9 question 6 (3 points) breana is selling tickets to a choral performance. on the first day of ticket sales, she sold 3 senior citizen tickets and 1 child ticket for a total of $38. breana took in $52 on the second day by selling 3 senior citizen tickets and 2 child tickets. what is the price of a senior citizen ticket? question 6 options: question 7 (3 points) a farmer has 5 times as many cows as pigs. the farmer only has cows and pigs, and he has 168 animals. how many cows does he have? question 7 options: 140 cows 120 cows 50 cows 28 cows question 8 (3 points) how many solutions does the system have? question 8 options: zero one infinitely many question 9 (3 points) what is the solution to the system of equations? graph of x+2y = 6 and y = x question 9 options: (1 , -2) (2, 2) (3, 5) (-2, 2)