Use the fraction models to solve the addition equation. There are two sets of fraction models. The first set has three fraction models, with two completely shaded, and the last one is partitioned into twelve equal parts with four parts shaded. The second set has two fraction models, with one completely shaded, and the last one is partitioned into six equal parts, with three parts shaded. Below is the equation two and four twelfths plus one and three sixths equals blank line.

three and seven twelfths
three and ten twelfths
three and seven eighteenths
two and twelve seventy seconds

(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.