Mrs. Doris' kindergarten class is making Valentines day cards for the parents of the children. The class will be using three colors of construction paper: Pink, Red, and Purple. Mrs. Doris needs to find out the cost of the project so she can shop for the supplies duirng the weekend. She wrote the expression: np +(nr + nu) N=the number of cards made. p=the pink paper, r=the red paper, u=the purple paper. Of the following expression which is equivalent to her expression?
1. n(pru), 2. p+n(r+U), 3. n(p+r+u), or none.