Simplify (x+y)(x-y)(x^2+y^2)

When i'm with my factor 5, my prodect is 20 .when i'm with my addend 6' my sum is 10.what number am i

Ateacher wanted to buy a chair, a bookshelf, two tables and a desk. she spent $900 for all five items and the chair and the desk combined 70% of her total. if the bookshelf cost $50, how much did each of the tables cost?

70 points ! pls 2. given the following two sets of data what is the union of the two sets and what is the intersection of the two sets. set a = {1, 2, 3, 4, 5, 6, 7, 8, 9} set b = {2, 4, 6, 8, 10, 12, 14} 3. given a regular deck of cards. describe a way of pulling cards that would create a dependent event and then one that would create an independent event. 4. what is the probability of drawing a red card and then drawing a spade without replacing the card that was drawn first?