下列计算正确的是 ( )
a 3 ⋅ a 2 = a 6
a 2 + a 2 = a 4
( a 3 ) 2 = a 5
a 3 a 2 = a ( a ≠ 0 )
下列运算正确的是 ( )
2 a - a = 2
( a - 1 ) 2 = a 2 - 1
a 6 ÷ a 3 = a 2
( 2 a 3 ) 2 = 4 a 6
2 a - a = 1
2 a ⋅ ( - 3 a ) = - 6 a 2
( a 2 ) 3 = a 5
a + a 2 = a 3
( 2 a 2 ) 3 = 2 a 6
a 6 ÷ a 2 = a 3
a 3 ⋅ a 2 = a 5
x 3 + x 3 = x 6
2 x 3 - x 3 = x 3
( x 3 ) 2 = x 5
x 3 ⋅ x 3 = x 9
下列运算中,正确的是( )
a 2 • a 5 = a 10
( a ﹣ b ) 2 = a 2 ﹣ b 2
(﹣ 3 a 3 ) 2 = 6 a 6
﹣ 3 a 2 b + 2 a 2 b =﹣ a 2 b
a 5 + a 5 = a 10
- 3 ( a - b ) = - 3 a - 3 b
( ab ) - 3 = a b - 3
a 6 ÷ a 2 = a 4
7 a 3 - 3 a 2 = 4 a
- a ( - a + 1 ) = a 2 - a
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
3 a + 2 b = 5 ab
5 a 2 - 2 b 2 = 3
7 a + a = 7 a 2
( x - 1 ) 2 = x 2 + 1 - 2 x
计算: 2 a + 3 a = .
计算 4 a + 2 a - a 的结果等于 .
计算: 2 a 2 - ( a 2 + 2 ) = .