计算: 9 + 2 sin 60 ∘ + | 3 - 3 | - ( 2016 - π ) 0 .
解方程组 x + y = 5 2 x + y = 11 .
先化简,再求值: a + 3 a ⋅ 6 a 2 + 6 a + 9 + 2 a - 6 a 2 - 9 ,其中 a = 3 - 1 .
计算: | - 3 | - 2016 + sin 30 ∘ 0 - - 1 2 - 1 .
计算: | - 2 | - 2 cos 60 ∘ + 1 6 - 1 - ( π - 3 ) 0 .