计算5x2y•(-3xy3)=_______;-3xy(2x-3y)=_______.
计算:(-9x2+3x)(-3x)=______.
计算:4x•(2x2-3x+1)=_______.
.
下列各式计算正确的是( ).
A.(a-3b)(-6a)=-6a2-18ab
B.(-
x2y)(-xy+1)=
x3y2+1
C.(
a2b)2·(-4ab2)=4a3b4
D.(
ab2-2ab)(-
ab)=-
a2b3+a2b2
a3-2a(3a-4b+5c)的计算结果是( )
A.a3+6a+8ab-10abc
B.a3-6a2+8ab-10ac
C.a2-6a3+8ab+10ac
D.a3-6a2-8ab+10abc
