The following formula models the number of automobiles, a, in thousands, that washington residents purchased x years after 1980. a = 2 x 2 + 22 x + 322 a=2x2+22x+322 a) write an equation that you can use to determine the first year in which residents purchased approximately 874 thousand cars. b) now solve your equation by factoring and specify the first year in which residents purchased approximately 874 thousand cars.