赚现金
(1)计算: - 1 4 + 12 sin 60 ∘ + ( 1 2 ) - 2 - ( π - 5 ) 0
(2)先化简,再求值: ( 1 - 1 x + 2 ) ÷ x 2 + 2 x + 1 x + 2 ,其中 x = 3 - 1 . .
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