1、,15.2.3 积的乘方,15.2.3 积的乘方,探究组卷网 填空,看看运算过程用到哪些运算律?运算结果有什么规律? (1) (ab)2=(ab) (ab)=(aa) (bb)=a( )b ( ); (2) (ab)3= _ = _ =a ( )b( ).,即积的乘方,等于把积的每一个因式分别乘方,再把所得的幂相乘.,例3 计算:(1) (2a)3 ; (2) (-5b)3 ;(3) (xy2)2 ; (4) (-2x3)4.,解: (1) (2a)3=23a3 = 8a3；中学学科网(2) (-5b)3=(-5)3b3=-125b3；(3) (xy2)2=x2(y2)2=x2y4；(4) (
2、-2x3)4=(-2)4(x3)4=16x12.,练习组卷网 计算: (ab)4 ; (2) (-2xy)3; (3) (-3102)3 ; (4) (2ab2)3.,a4b4 ; (2) 8x3y3; (3) 2.7107; (4) 8a3b6.,思维延伸,已知,xm= ,xn=3.求下列各式的值: (1)x m+n; (2) x2mx2n; (3) x 3m+2n.,解: (1) x m+n=x mx n= 3= ; (2) x2mx2n=(x m )2(x n)2=( )232= 9 = ; (3) x 3m+2n=x3mx2n=(x m)3(x n)2=( )332= 9 = zxxkw,再见,
