下列计算正确的是 ( )
A. 2 x − x = 1 B. x ( − x ) = − 2 x
C. ( x 2 ) 3 = x 6 D. x 2 + x = 2
下列运算正确的是 ( )
A. 2 a − a = 1 B. 2 a + b = 2 ab
C. ( a 4 ) 3 = a 7 D. ( − a ) 2 · ( − a ) 3 = − a 5
A. a ( a + 1 ) = a 2 + 1 B. ( a 2 ) 3 = a 5
C. 3 a 2 + a = 4 a 3 D. a 5 ÷ a 2 = a 3
A. 3 m - m = 2 B. m 4 ÷ m 3 = m C. ( - m 2 ) 3 = m 6 D. - ( m - n ) = m + n
A. a 3 + a 2 = 2 a 5 B. ( - a b 2 ) 3 = a 3 b 6
C. 2 a ( 1 - a ) = 2 a - 2 a 2 D. ( a + b ) 2 = a 2 + b 2
a ⋅ a 2 = a 3
a 6 ÷ a 2 = a 3
2 a 2 - a 2 = 2
( 3 a 2 ) 2 = 6 a 4
a 3 + a 2 = a 5
a 3 ÷ a 2 = a
a 3 · a 2 = a 6
( a 3 ) 2 = a 9
下列计算中,正确的是 ( )
( a 3 ) 4 = a 12
a 3 · a 5 = a 15
a 2 + a 2 = a 4
3 2 - 2 = 3
a 6 ÷ a 3 = a 2
a 2 + a 3 = a 5
( 3 a 3 ) 2 = 9 a 6
A. 2 y 3 + y 3 = 3 y 6 B. y 2 ⋅ y 3 = y 6 C. ( 3 y 2 ) 3 = 9 y 6 D. y 3 ÷ y − 2 = y 5
下列各式中,运算正确的是 ( )
A. ( a 3 ) 2 = a 5 B. ( a − b ) 2 = a 2 − b 2
C. a 6 ÷ a 2 = a 4 D. a 2 + a 2 = 2 a 4
A. a 8 ÷ a 4 = a 2 B. ( a 2 ) 2 = a 4
C. a 2 · a 3 = a 6 D. a 2 + a 2 = 2 a 4
A. a 2 + 2 a = 3 a 3 B. ( − 2 a 3 ) 2 = 4 a 5
C. ( a + 2 ) ( a − 1 ) = a 2 + a − 2 D. ( a + b ) 2 = a 2 + b 2
A. − ( x − y ) 2 = − x 2 − 2 xy − y 2 B. a 2 + a 2 = a 4
C. a 2 · a 3 = a 6 D. ( x y 2 ) 2 = x 2 y 4
A. a 3 · a 2 = a 6 B. ( − a 2 ) 3 = a 6
C. a 7 ÷ a 5 = a 2 D. − 2 mn − mn = − mn