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 .
计算: ( π - 1 ) 0 + 8 - 4 sin 45 ° .
计算: ( 2021 - π ) 0 - | 3 - 2 | - tan 60 ° .
计算: ( 2 - 1 ) 0 + | - 3 | - 27 3 + ( - 1 ) 2021 .
计算: − 1 2 + ( π − 2021 ) 0 + 2 sin 60 ° − | 1 − 3 | .
计算: | 2 − 1 | + cos 45 ° − ( 2 ) − 3 + 8 .
计算 | 2 - 2 | + 2 sin 45 ° - ( - 1 ) 2 .
计算: ( 2021 π ) 0 + ( 1 4 ) - 1 - ( - 4 ) + 2 3 cos 30 ° .
计算: | - 2 | - 2 sin 45 ° + ( 1 - 3 ) 0 + 2 × 8 .
计算: ( - 1 ) 2021 + 8 - 4 sin 45 ° + | - 2 | .
计算: | 1 - 3 | - 2 sin 60 ° + ( π - 1 ) 0 .
计算: 2021 0 + 3 - 1 ⋅ 9 - 2 sin 45 ° .
(1)计算: 4 × ( - 3 ) + | - 8 | - 9 + ( 7 ) 0 .
(2)化简: ( a - 5 ) 2 + 1 2 a ( 2 a + 8 ) .
(1)计算: 8 + ( π + 2 ) 0 + ( - 1 ) 2021 - 2 cos 45 ° ;
(2)解分式方程: x - 3 x - 2 + 1 = 3 2 - x .
(1)计算: ( 1 2 ) - 2 + ( 3 . 14 - π ) 0 + | 3 - 12 | - 4 sin 60 ° .
(2)先化简,再求值: ( 1 x - 1 - x + 1 ) ÷ x - 2 x 2 - 1 ,其中 x = 2 - 1 .
(1)计算: ( - 1 ) 2 - ( π - 2021 ) 0 + | - 1 2 | ;
(2)如图,在 ΔABC 中, ∠ A = 40 ° , ∠ ABC = 80 ° , BE 平分 ∠ ABC 交 AC 于点 E , ED ⊥ AB 于点 D ,求证: AD = BD .