新冀教版2024七年级数学下册第八章《8.2 第1课时 幂的乘方》习题课件.pptx

第八章,整式的乘法,8.2,幂的乘方与积的乘方,第,1,课时 幂的乘方,幂的乘方,1,.,若,k,为正整数,则,(,k,2,),3,表示的是,(,),A,.,3,个,k,2,相加,B,.,2,个,k,3,相加,C,.,3,个,k,2,相乘,D,.,2,个,k,3,相乘,2,.,2023,石家庄二十一中月考,计算,-(,m,2,),3,的结果是,(,),A.-,m,6,B.,m,6,C.-,m,5,D.,m,5,C,A,3,.,计算,(,a,m,),3,a,n,的结果是,(,),A.,am,3,+,n,B.,a,3,m,+,n,C.-,a,3,mn,D.-,a,3,m,+,n,4,.,下列计算正确的是,(,),A.,a,3,+,a,4,=,a,7,B.,a,3,a,4,=,a,12,C.(,a,3,),4,=,a,12,D.(,a,2,),4,=,a,7,5,.,如果,9,n,=3,4,那么,n,=,.,D,C,2,6,.,计算,:,(,1,),(10,2,),3,;,(,2,),(,x,3,),7,;,(,3,),(-,a,),8,5,;,(,4,),2(,m,5,),2,+(,m,2,),5,.,解,:,(10,2,),3,=10,23,=10,6,.,解,:,(,x,3,),7,=,x,37,=,x,21,.,解,:,(-,a,),8,5,=(,a,8,),5,=,a,85,=,a,40,.,解,:,2(,m,5,),2,+(,m,2,),5,=2,m,52,+,m,25,=3,m,10,.,幂的乘方的逆用,7,.,在下列各式的框内,应填入,b,4,的是,(,),A.,b,12,=,8,B.,b,12,=,6,C.,b,12,=,3,D.,b,12,=,2,8.,若,(,a,2,),3,a,m,=,a,10,则,m,=,.,C,4,9,.,已知,a,m,=2,b,n,=5,求,(,a,3,),m,(,b,2,),n,的值,.,解,:,(,a,3,),m,(,b,2,),n,=,a,3,m,b,2,n,=(,a,m,),3,(,b,n,),2,=2,3,5,2,=200,.,10,.,如果正方体的棱长是,(,a,+,b,),3,那么这个正方体的体积是,(,),A.(,a,+,b,),6,B.6(,a,+,b,),6,C.(,a,+,b,),9,D.(,a,+,b,),12,11,.,2023,唐山十二中期末,已知,2,m,+3,n,=6,则,4,m,8,n,=,(,),A.16 B.25 C.32D.64,12,.,已知,2,2,4,n,8,n,=2,1,7,则,n,=,.,13,.,若,x,+3,y,-3=0,则,2,x,8,y,=,.,C,D,3,8,14,.,已知,16,m,=42,2,n,-2,27,n,=93,m,+3,求,(,n,-,m,),2 025,的值,.,解,:,由题意,知,(2,4,),m,=2,2,2,2,n,-2,(3,3,),n,=3,2,3,m,+3,即,2,4,m,=2,2,n,3,3,n,=3,m,+5,所以,4,m,=2,n,3,n,=,m,+5,解得,m,=1,n,=2,.,所以,(,n,-,m,),2 025,=1,.,15,.,已知,3,x,=,a,4,x,=,b,求,:,(,1,),9,x,的值,;,(,2,),81,x,+16,x,的值,.(,结果用含,a,b,的代数式表示,),解,:,9,x,=(3,2,),x,=3,2,x,=(3,x,),2,=,a,2,.,解,:,81,x,+16,x,=(3,4,),x,+(4,2,),x,=(3,x,),4,+(4,x,),2,=,a,4,+,b,2,.,16,.,阅读,:,已知正整数,a,b,c,显然,当底数相同时,指数大的幂也大,若对于相同指数,不同底数的两个幂,a,b,和,c,b,当,a,c,时,则有,a,b,c,b,.,根据上述材料,回答下列问题,:,(,1,),比较大小,:,5,20,4,20,;(,填“,”“,解,:,2,33,=(2,3,),11,=8,11,3,22,=(3,2,),11,=9,11,因为,98,所以,8,11,9,11,.,所以,2,33,3,22,.,。