To open a combination lock, you turn the dial to the right and stop at a number; then you turn it to the left and stop at a second number. finally, you turn the dial back to the right and stop at a third number. if you used the correct sequence of numbers, the lock opens. if the dial of the lock contains 9 numbers, 0 through 8, determine the number of different combinations possible for the lock. note: the same number can be reused consecutively. incorrect: your answer is incorrect.

(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.