Pens cost $0.35 each and books cost $4.90 each. A particular customer spent a total of $21.30. Which equation correctly describes the number of pens and books purchased? A. 0.35p - 4.90b = 21.30
B. 0.35b - 4.90p = 21.30
C. 0.35p + 4.90b = 21.30
D. 0.35b + 4.90p = 21.30

() at a farm, animals are fed bales of hay and buckets of gain. each bale of hay is in the shape of a rectangular prism. the base side lengths 2 feet and 3 feet, and the height is 5 feet. each bucket of grain is a cylinder with diameter of 3 feet. the height of the bucket is 5 feet as the height of bale. a. which is larger in area, the rectangular base of the bale or the circular base of the bucket? explain how you know b. which is larger in volume, the bale or the bucket? explain how you know

This is different from the first one can someone me

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a. m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?