计算:.
计算: ( - 1 + 2 ) × 3 + 2 2 ÷ ( - 4 ) .
计算: 3 2 + ( ﹣ 2 ) 0 ﹣ 17 .
计算: ( 1 + 1 x ) ÷ ( x 2 + x ) x .
解不等式: 2 ( x ﹣ 3 ) < 8 .
化简: ( x + 3 ) 2 x + 2 ÷ x 2 + 3 x x + 2 - 3 x .