Find the sum of the geometric series. a{1}=88, a{5}=1408, r=-2

Igor stravinsky tires sells approximately 3,760,000 car tires and 1,200,000 truck tires each year. about 47,000,000 care tires and 26,000,00 truck tires are sold each year in the united states. what is stravinsky's market share in each of these two markets (cars and trucks)?

How do you use the elimination method for this question? explain, because i really want to understand!

If rt is greater than ba, which statement must be true ?