 United follows rival Delta Airlines in saying price cuts by low-cost carriers struggling to fill in excess of seats this summer are weighing on the entire industry. Darden Restaurants is adding another chain to its stable of eateries. The parent of Olive Garden, Longhorn Steakhouse, and other brands is going Tex-Mex. The company is buying Texas-based Chewy's, which has about 100 locations. The price tag on the all-cash deal is about $605 million. The takeover expect