化简 8 的正确结果是 ( )
4
± 4
2 2
± 2 2
下列计算正确的是 ( )
2 2 = 2
( - 2 ) 2 = - 2
2 2 = ± 2
( - 2 ) 2 = ± 2
已知 a , b 满足等式 a 2 + 6 a + 9 + b − 1 3 = 0 ,则 a 2021 b 2020 = .
2 + 3 = 5
( − 3 ) 2 = ± 3
a ⋅ a − 1 = 1 ( a ≠ 0 )
( − 3 a 2 b 2 ) 2 = − 6 a 4 b 4
观察下列各等式:
① 2 2 3 = 2 + 2 3 ;
② 3 3 8 = 3 + 3 8 ;
③ 4 4 15 = 4 + 4 15 ;
…
根据以上规律,请写出第5个等式: .
3 a 2 + 4 a 2 = 7 a 4
a 2 ⋅ 1 a = 1
− 18 + 12 ÷ ( − 3 2 ) = 4
a 2 a − 1 − a − 1 = 1 a − 1
计算 ( 3 ) 2 的结果是 ( )
3
2 3
9
计算: ( - 5 ) 2 = .
计算: - 4 × 1 2 = ( )
- 2 2
- 2
2、5、 m 是某三角形三边的长,则 ( m - 3 ) 2 + ( m - 7 ) 2 等于 ( )
2 m - 10
10 - 2 m
10
计算 ( - 5 ) 2 的结果是 .
下列运算正确的是 ( )
( - x 3 ) 2 = x 5
( - x ) 2 = x
( - x ) 2 + x = x 3
( - 1 + x ) 2 = x 2 - 2 x + 1
对于任意两个不相等的数 a , b ,定义一种新运算“ ⊕ ”如下: a ⊕ b = a + b a - b ,如: 3 ⊕ 2 = 3 + 2 3 - 2 = 5 ,那么 12 ⊕ 4 = .
下列等式成立的是 ( )
A. ( 3 ) 2 = 3 B. ( − 3 ) 2 = − 3 C. 3 3 = 3 D. ( − 3 ) 2 = − 3
A. 2 + 3 = 5 B. 18 = 2 3
C. 2 ⋅ 3 = 5 D. 2 ÷ 1 2 = 2