(1)3a 2•2a 3=6a 5;
(2)(-9a 2b 3)•8ab 2=-72a 3b 5;
(3)(-2x) 2•(-3x 2)=4x 2•(-3x 2)=-12x 4;
(4)(-a 2) 3•(-2a 2) 3;=-a 6•(-8a 6)=8a 12;
(5)m 2n•(-0.5m 3n 2)•2mn 2=-m 6n 5.
(1)3a 2•2a 3=6a 5;
(2)(-9a 2b 3)•8ab 2=-72a 3b 5;
(3)(-2x) 2•(-3x 2)=4x 2•(-3x 2)=-12x 4;
(4)(-a 2) 3•(-2a 2) 3;=-a 6•(-8a 6)=8a 12;
(5)m 2n•(-0.5m 3n 2)•2mn 2=-m 6n 5.