计算:(每小题8分,共16分)(1) ×÷ (2) +6-2x
(眉山)(本小题满分6分)计算:.
(泸州)计算:.
(泸州)化简:.
(凉山州)计算:.
(凉山州)先化简:,然后从的范围内选取一个合适的整数作为x的值代入求值.