Michael Franklin has $19,000 invested in stock A and stock B. Stock A currently sells for $50 a share and stock B sells for $90 a share.

Michael Franklin has ​$19,000 invested in stock A and stock B. Stock A currently sells for ​$50 a share and stock B sells for ​$90 a share. If stock B triples in value and stock A goes up​ 50%, his stock will be worth ​$42,000. How many shares of each stock does he ​own?