Solutions to the quadratic equation x^2+3x-28=0

I'm so close to finishing all these.

Why did the ice arena get so hot after the big game (this is math related google it to find the paper

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?