tan(π-α)＝2→tanα＝-2.(1)(2sinα+2cosα)/(7sinα+cosα)＝[2(sinα/cosα)+2]/[7(sinα/cosα)+1]＝(-4+2)/(-14+1)＝2/13.(2)sinαcosα＝sinααcosα/(sin²α+cos²α)＝(sinα/cosα)/[(sinα/cos...