若,则= .
下列运算正确的是( )
下列计算正确的是( ).
下列计算正确的是 ( )
( x 2 ) 3 = x 5
x 2 + x 2 = x 4
x 2 ⋅ x 3 = x 5
x 6 ÷ x 3 = x 2
若a2+2a-3=0,则代数式2a2+4a的值等于
已知单项式3amb2与﹣的和是单项式,那么m+n= .
分解因式:x3﹣4x= .
下列式子正确的是( )
下列运算中,正确的是 ( )
a 2 + a = a 3
( - ab ) 2 = - a b 2
a 5 ÷ a 2 = a 3
a 5 ⋅ a 2 = a 10
计算: 2 a + 3 a = .
a 2 + a 2 = 2 a 4
a 2 ⋅ a = a 3
( 3 a ) 2 = 6 a 2
a 6 + a 2 = a 3
下列运算正确的是 ( )
2 x 2 + 3 x 3 = 5 x 5
( − 2 x ) 3 = − 6 x 3
( x + y ) 2 = x 2 + y 2
( 3 x + 2 ) ( 2 − 3 x ) = 4 − 9 x 2
下列式子正确的是 ( )
a 3 - a 2 = a
( a 2 ) 3 = a 6
a 3 ⋅ a 2 = a 6
( a 2 ) 3 = a 5
先化简,再求值:3-[7x-2(6x-8)-],其中x=-1.
2(a-b)-3(a+b)