1、 1≤3x+2y≤ 17(3 * 1-2 * 1≤3x+2y≤3 * 3+2 * 4)

2、(4-π)/4 ( 1-(? πa？ )/a？ )

3. Right (because A+B ≤ 180)

4, 0<a< 1 (two different numbers x? *X？ =lg(2a？ A) < 0 There must be 2a in the simultaneous logarithm. ﹣a>0)

answer the question

1

(1) If a=3 and the inequality is (x-3) ÷ (x+ 1) < 0, then (x-3) and (x+ 1) are different symbols.

(x-3)*(x+ 1)