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Why are gold and platinum used for jewelry

When looking at research about instructional strategies, make sure the research is a. from peer-reviewed studies. b. approved by state and federal government organizations. c. online and easily accessible. d. about the same topic you're interested in.

Case # 51173878 weighs 814 pounds; case # 51173981 weighs 803 pounds; case # 51174058 weighs 817 pounds; case 51174178 weighs 815 pounds; case # 51174248 weighs 817 pounds; case # 51174495 weighs 781 pounds; case # 51174577 weighs 828 pounds. what are the case #'s of the two cases that weigh the same amount?