Solve the problem.Two phone companies compete for customers in a city. Company 1 retains 3/4 of its customers and loses 1/4 of its customers to Company 2. Company 2 retains 5/6 of its customers and loses 1/6 to Company 1. If we represent the fraction of the market held last year by , where a is the number the that Company 1 had last year and b is the number that Company 2 had last year, then the number that each company will have this year can be found by the following matrix equation.  = 

style="vertical-align: -15.0px;" />If Company 1 has A = 90,000 customers and Company 2 has B = 198,000 customers this year, how many customers did Company 1 have last year?



A. 216,000 customers

B. 72,000 customers

C. 76,000 customers

D. 222,000 customers

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Answer: B

Mathematics