下列运算正确的是 ( )
a - 2 = - a 2
a 2 + a 3 = a 5
a 2 ⋅ a 3 = a 6
( a 2 ) 3 = a 6
( - x 3 ) 2 = x 5
( - x ) 2 = x
( - x ) 2 + x = x 3
( - 1 + x ) 2 = x 2 - 2 x + 1
下列计算正确的是 ( )
a 3 + a 2 = a 5
a 3 ÷ a 2 = a
3 a 3 ⋅ 2 a 2 = 6 a 6
( a - 2 ) 2 = a 2 - 4
7 a 3 - 3 a 2 = 4 a
( a 2 ) 3 = a 5
a 6 ÷ a 3 = a 2
- a ( - a + 1 ) = a 2 - a
a 2 ⋅ a = a 3
5 a - 4 a = 1
( 2 a ) 3 = 6 a 3
下列运算中,计算正确的是 ( )
m 2 + m 3 = 2 m 5
( - 2 a 2 ) 3 = - 6 a 6
( a - b ) 2 = a 2 - b 2
6 ÷ 2 = 3
( - a ) 2 = - a 2
2 a 2 - a 2 = 2
( a - 1 ) 2 = a 2 - 1
不一定相等的一组是 ( )
a + b 与 b + a
3 a 与 a + a + a
a 3 与 a ⋅ a ⋅ a
3 ( a + b ) 与 3 a + b
a 3 + a 3 = a 6
2 a 3 - a 3 = 1
a 2 ⋅ a 3 = a 5
a 5 + a 5 = a 10
- 3 ( a - b ) = - 3 a - 3 b
( ab ) - 3 = a b - 3
a 6 ÷ a 2 = a 4
a 2 + a 2 = a 4
2 a - a = 1
2 a ⋅ ( - 3 a ) = - 6 a 2
2 a - a = 2
( 2 a 3 ) 2 = 4 a 6
下列运算正确的是( )
A. ( a 3 ) 4 = a 12 B. a 3 • a 4 = a 12 C. a 2 + a 2 = a 4 D. ( ab ) 2 = a b 2
A. a 2 + a 3 = a 5 B. a 2 · a 3 = a 5 C. a 3 ÷ a 2 = a 5 D. ( a 2 ) 3 = a 5
A. 2 a + 3 b = 5 ab B. a 3 · a 2 = a 5 C. ( a + b ) 2 = a 2 + b 2 D. ( a 2 b ) 3 = a 6 b