来自田馨的问题
concertticketsIn$400,$200and$100eachareavailableforsale.thenumberof$200ticketssoldisa4timesasmanyasthatof$400tickets.thenumberof$100ticketssoldis380morethanthatof$200tickets.ifthetotalincomefromtesaleoft
concertticketsIn$400,$200and$100eachareavailableforsale.thenumberof$200ticketssoldisa4timesasmanyasthatof$400tickets.thenumberof$100ticketssoldis380morethanthatof$200tickets.ifthetotalincomefromtesaleofticketsis$86000,howmany$400ticketsaresold?
