Carly beat the school record for the 400 meter run by 1.3 seconds. if she ran the race in 55.7 seconds, what was the record

Sum is 17 and their difference is 3

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?

What is the slope of (0,32) and (100,212)