计算(1)(2)
计算: ( π - 3 ) 0 + | - 2 | - 20 ÷ 5 + ( - 1 ) - 1 .
计算: 12 + ( π - 3 ) 0 - 2 cos 30 ∘ .
解不等式组: 2 x - 6 < 0 ⋯ ① 1 - x < 0 ⋯ ② .
计算: ( 2 π ) 0 + | - 6 | - 8 3 .
先化简再求值: x + 1 - 3 x - 1 ⋅ x - 1 x - 2 ,其中 x = 2 + 2 .