Over three month pd store receives 1770lbs dogfood, 1165 lbs cat food and 365 lbs bird seed. 1st month 60% dogfood, 25% cat food and 15% birdseed. 2nd month 50% dogfood, 35% cat food and 15% bird seed, 3rd month 50% dogfood, 45% cat food, and 5% bird seed. write and solve x, y, z equations to find the #of pounds of each pet food in each of the three shipmenrts.