A playground is being designed where children can interact with their friends in certain combinations. If there is 1 child, there can be 0 interactions. If there are 2 children, there can be 3 interactions. If there are 3 children, there can be 9 interactions. If there are 4 children, there can be 18 interactions. How many interactions will there be for 9 children?

The weight v of an object on venus varies directly with its weight e on earth. a person weighing 120 lb on earth would weigh 106 lb on venus. how much would a person weighing 150 lb on earth weigh on venus?

Use the quadratic function to predict f(x) if x equals 8. f(x) = 25x2 − 28x + 585

(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.