Richard is designing a new website for students to create study groups and collaborate with other students. the site will launch with five study groups, each with its creator as its only member, and richard anticipates that two study groups will be added every month. he also estimates that seven new members will be added to each study group every month. the estimate for the total number of group members is given by the polynomial expression below, where x is the number of months since the site's launch.

(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.