下列计算正确的是 ( )
2 + 3 = 5
( − 3 ) 2 = ± 3
a ⋅ a − 1 = 1 ( a ≠ 0 )
( − 3 a 2 b 2 ) 2 = − 6 a 4 b 4
计算: 4 + ( - 1 ) 0 = .
计算: 4 - ( - 1 ) 2 - ( π - 1 ) 0 + 2 - 1 .
计算: | - 2021 | + ( - 3 ) 0 - 4 .
计算: 9 1 2 + | 1 − 2 | − 2 − 1 × 8 .