下列计算正确的是 ( )
a 2 ⋅ a 3 = a 6
a 2 + a 3 = a 5
( a 2 ) 3 = a 6
a 2 ÷ a 3 = a
下列各式中,正确的是 ( )
x + 2 x = 3 x 2
− ( x − y ) = − x − y
( x 2 ) 3 = x 5
x 5 ÷ x 3 = x 2
下列运算正确的是 ( )
a + a 2 = a 3
( 2 a 2 ) 3 = 2 a 6
a 6 ÷ a 2 = a 3
a 3 ⋅ a 2 = a 5
计算: x 7 ÷ x 2 = .
a 2 + a = a 3
( a 2 ) 3 = a 5
a 8 ÷ a 2 = a 4
a 2 ⋅ a 3 = a 5
5 a 2 - 4 a 2 = 1
( - a 2 b 3 ) 2 = a 4 b 6
a 9 ÷ a 3 = a 3
( a - 2 b ) 2 = a 2 - 4 b 2
a 2 ⋅ a 4 = a 8
− a ( a − b ) = − a 2 − ab
( − 2 a ) 2 ÷ ( 2 a ) − 1 = 8 a 3
( a − b ) 2 = a 2 − b 2
x 2 + x 2 = x 4
x 2 ⋅ x 3 = x 5
x 6 ÷ x 3 = x 2
x 2 ⋅ x = 2 x 2
( x y 3 ) 2 = x 2 y 6
x 2 + x = x 3
( x 2 ) 3 = x 6
3 x 2 - 2 x = x
( - 2 x ) 3 = - 6 x 3
x 6 ÷ x 2 = x 3
下列运算中,正确的是 ( )
( - ab ) 2 = - a b 2
a 5 ÷ a 2 = a 3
a 5 ⋅ a 2 = a 10
2 a + 3 a = 6 a
2 x 2 + 3 x 2 = 5 x 2
x 2 ⋅ x 4 = x 8
( x y 2 ) 2 = x y 4
下列计算中,正确的是 ( )
( a + 3 ) 2 = a 2 + 9
a 8 ÷ a 4 = a 2
2 ( a - b ) = 2 a - b
a 2 + a 2 = 2 a 2
x 2 + x 3 = x 5
( x - y ) 2 = x 2 - y 2