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1.1同底数幂的乘法练习题

北师大版初中数学7年级(下)第1章 整式的乘除:1.1 同底数幂的乘法练习题库一.选择题(共20小题)1.计算3a a 的结果正确的是( ) A .3aB .4aC .3aD .43a2.下列计算正确的是( ) A .23a a a =B .23a a a +=C .339a a a =D .336a a a +=3.23()()(a b b a --= ) A .5()b a -B .5()b a --C .5()a b -D .5()a b --4.计算:24()a a -的结果是( ) A .8aB .6a -C .8a -D .6a5.若4822a =,则a 等于( ) A .2B .4C .16D .186.计算23(2)(2)(2)-⨯-⨯-的结果是( ) A .64-B .32-C .64D .327.若x ,y 为正整数,且5222x y =,则x ,y 的值有( ) A .4对B .3对C .2对D .1对8.下列计算中正确的是( ) A .3332a a a =B .333a a a =C .336a a a =D .3362a a a =9.在(a 4)a =中,括号内的代数式应为( ) A .2aB .3aC .4aD .5a10.若x ,y 为正整数, 且29222x y =,则x ,y 的值有( ) A . 1 对B . 2 对C . 3 对D . 4 对11.计算33m m 的结果是( ) A .6mB .9mC .32mD .3m12.若3x a =,2y a =,则x y a +等于( )A .6B .7C .8D .1813.已知2a x =,3b x =,则32(a b x += ) A .17B .72C .24D .3614.若2530x y +-=,则432x y 的值为( ) A .8B .8-C .18D .18-15.23a a ⨯的结果是( ) A .6aB .5aC .62aD .52a16.若220x y +-=,则931x y ⨯-的值为( ) A .10-B .8C .7D .617.已知31a =,32b =,则3a b +的值为( ) A . 1B . 2C . 3D . 2718.若23x =,25y =,则2(x y += ) A .11B .15C .30D .4519.已知2m x =,3n x =,则m n x +的值是( ) A .5B .6C .8D .920.已知8m a =,16n a =,则m n a +等于( ) A .24B .32C .64D .128二.填空题(共20小题)21.若5m a =,6n a =,则m n a += . 22.已知4m x =,3n x =,则m n x +的值为 . 23.若3m a =,4n a =,则m n a += .24.用()x y +的幂的形式表示:34()()x y x y +--= .25.已知310m a a a =,则m = .26.235()()()b b b ---= .27.如果1012m =,103n =,那么10m n += .28.若x ,y 为正整数,且2216x y =,则x ,y 的值是 .29.计算:23a a a .31.若32n =,则23n = .32.已知3n a =,3m b =,则13m n ++= 33.若39m a a a =,则m = . 34.计算:2a 6a =.35.已知83273n ⨯=,则n 的值是 . 36.计算34x x x +的结果等于 .37.已知2530m n ++=,则432m n ⨯的值为 . 38.已知72162x ⨯=,那么x = .39.已知3a x =,4b x =,则a b x += .40.计算32()a a --= . 三.解答题(共20小题)41.规定两数a ,b 之间的一种运算,记作(,)a b ,如果c a b =,则(,)a b c =.我们叫(,)a b 为“雅对”.例如:因为328=,所以(2,8)3=.我们还可以利用“雅对”定义说明等式(3,3)(3+,5)(3=,15)成立.证明如下:设(3,3)m =,(3,5)n =,则33m =,35n =, 故3333515m n m n +==⨯=, 则(3,15)m n =+,即(3,3)(3+,5)(3=,15).(1)根据上述规定,填空:(2,4)= ;(5,1)= ;(3,27)= . (2)计算(5,2)(5+,7)= ,并说明理由.(3)利用“雅对”定义证明:(2n ,3)(2n =,3),对于任意自然数n 都成立. 42.已知5x a =,25x y a +=,求x y a a +的值.43.若32125m m a a a a +=,求m 的值.44.已知1382162m m ⨯⨯=,求m 的值.46.计算:2533a a a a a +.47.计算:234()()()()a b b a a b b a --+--48.已知:213178222m m -=,求m 的值.49.利用幂的运算性质计算:.50.已知3m a =,6n a =,4k a =,求m n k a ++的值.51.若2228162n n =,求n 的值.52.已知25a =,23b =,求32a b ++的值.53.一个长方形的长是44.210cm ⨯,宽是4210cm ⨯,求此长方形的面积及周长.54.已知62111b b x x x -+=,且145a b y y y --=,求a b +的值.55.计算:(1)20112012(8)(0.125)-- (2)53()()a b b a --56.计算:(1)32a a a (2)2009200820105()(1.2)(1)6-⨯⨯-.57.234()()a a a a -- 58.53134()()n n x x x x --+-59.235()()()()()x x x x x ---+-- 60.23()()x y x y --北师大版初中数学7年级(下)第1章 整式的乘除:1.1 同底数幂的乘法练习题库参考答案与试题解析一.选择题(共20小题) 【解答】解:34a a a =. 故选:B .【解答】解:A .23a a a =,此选项正确;B .a 与2a 不是同类项,不能合并,此选项错误;C .336a a a =,此选项错误;D .3332a a a +=,此选项错误;故选:A .【解答】解:23235()()()()()a b b a b a b a b a --=--=-. 故选:A .【解答】解:246()a a a -=. 故选:D .【解答】解:4822a =, 84422216a ∴=÷==.故选:C .【解答】解:23(2)(2)(2)-⨯-⨯-6(2)=- 64=.故选:C .【解答】解:222x y x y +=, 5x y ∴+=,x ,y 为正整数,x ∴,y 的值有1x =,4y =;2x =,3y =;3x =,2y =; 4x =,1y =.共4对. 故选:A .【解答】解:A 、结果是6a ,故本选项不符合题意;B 、结果是6a ,故本选项不符合题意;C 、结果是6a ,故本选项符合题意;D 、结果是6a ,故本选项不符合题意;故选:C .【解答】解:34a a a =, 故选:B .【解答】解:29222x y =,2922x y +∴=,29x y ∴+=,x ,y 为正整数, 920y ∴->,92y ∴<, 1y ∴=, 2 , 3 , 4故x ,y 的值有 4 对, 故选:D .【解答】解:336m m m =. 故选:A .【解答】解:3x a =,2y a =, 326x y x y a a a +∴==⨯=.故选:A .【解答】解:33()8a a x x ==,2()9b x =, 32328972a b a b x x x +=⨯=⨯=,故选:B .【解答】解:2543222x y x y =252x y += 32=8=,故选:A .【解答】解:235a a a ⨯=. 故选:B .【解答】解:220x y +-=, 22x y ∴+=, 293131x y x y +∴⨯-=- 231=- 91=- 8=.故选:B .【解答】解:33a b ⨯3a b += 3a b +∴ 33a b =⨯12=⨯ 2=故选:B .【解答】解:2223515x y x y +==⨯=, 故选:B . 【解答】解:2m x =,3n x =,236m n m n x x x +∴=⨯=⨯=.故选:B .【解答】解:816128m n m n a a a +==⨯=, 故选:D .二.填空题(共20小题)【解答】解:5m a =,6n a =, 5630m n m n a a a +∴==⨯=.故答案为:30 【解答】解:4m x =,3n x =,4312m n m n x x x +∴==⨯=.故答案为:12.【解答】解:3m a =,4n a =, 3412m n m n a a a +∴==⨯=.故答案为:12.【解答】解:原式34()()x y x y =++7()x y =+. 故答案是7()x y +.【解答】解:310m a a a =,310m ∴+=, 7m ∴=, 故答案为7.【解答】解:原式235()b ++=-10()b =- 10b =.故答案为:10b .【解答】解:10101012336m n m n +==⨯=. 故答案为:36.【解答】解:2216x y =,422x y +∴=,4x y ∴+=,x ,y 为正整数,∴13x y =⎧⎨=⎩或22x y =⎧⎨=⎩或31x y =⎧⎨=⎩,故答案为13x y =⎧⎨=⎩或22x y =⎧⎨=⎩或31x y =⎧⎨=⎩.【解答】解:236a a a a =. 故答案为:6a .【解答】解:25m =,29n =, 2225945m n m n +∴==⨯=.故答案为:45.【解答】解:2223(3)24n n ===. 【解答】解:3n a =,3m b =, 13333m n n m ++∴=⨯⨯ 3ab =.故答案为:3ab .【解答】解:由题意可知:39m +=, 6m ∴=,故答案为:6【解答】解:246a a a =. 故答案为:4a .【解答】解:83273n ⨯=, 38333n ∴⨯=, 3833n +∴=, 38n ∴+=,解得:5n =, 则n 的值是5. 故答案为:5.【解答】解:3442x x x x +=, 故答案为:42x 【解答】解:432m n ⨯,2522m n =⨯, 252m n +=,2530m n ++=,253m n ∴+=-,3143228m n -∴⨯==. 故答案为:18. 【解答】解:72162x ⨯=,47222x ∴⨯=,47x ∴+=,解得:3x =.故答案为:3.【解答】解:3a x =,4b x =,12a b a b x x x +∴=⨯=.故答案为:12.【解答】解:32()a a --32a a =-5a =-.故答案为:5a -.三.解答题(共20小题)【解答】解:(1)224=,(2,4)2∴=;051=,(5,1)0∴=;3327=,(3,27)3∴=;故答案为:2,0,3;(2)设(5,2)x =,(5,7)y =,则52x =,57y =,55514x y x y +∴==,(5,14)x y ∴=+,(5∴,2)(5+,7)(5=,14),故答案为:(5,14);(3)设(2n ,3)n x =,则(2)3n x n =,即(2)3x n n =所以23x =,即(2,3)x =,所以(2n ,3)(2n =,3).【解答】解:25x y a +=,25x y a a ∴=,5x a =,y a ∴,5=,5510x y a a ∴+=+=.【解答】解:32132125m m m m a a a a a ++++==,32125m m ∴+++=,解得7m =.故m 的值是7.【解答】解:1382162m m ⨯⨯=341322(2)2m m ∴⨯⨯=,3413m m ∴++=,2m ∴=【解答】解:8m a =,32n a =,832256m n m n a a a +∴==⨯=.【解答】解:2533a a a a a +77a a =+72a =.【解答】解:原式234()()()()b a b a b a b a =--+--,55()()b a b a =-+-,52()b a =-.【解答】解:由幂的乘方,得3213172222m m -=.由同底数幂的乘法,得32131722m m +-+=.即5217m +=,解得3m =,m 的值是3. 【解答】解:原式1113623222=⨯⨯⨯11123632++=⨯32=⨯6=.【解答】解:36472m n k m n k a a a a ++==⨯⨯=.【解答】解:2816n n ,34222n n =⨯⨯,712n +=,2228162n n =,7122n ∴+=,解得3n =.【解答】解:332222538120a b a b ++==⨯⨯=.【解答】解:面积=长⨯宽44824.2102108.410cm =⨯⨯⨯=⨯. 周长2=(长+宽)4452(4.210210) 1.2410cm =⨯+⨯=⨯. 综上可得长方形的面积为828.410cm ⨯.周长为51.2410cm ⨯.【解答】解:62111b b x x x -+=,且145a b y y y --=, ∴62111145b b a b -++=⎧⎨-+-=⎩, 解得:64a b =⎧⎨=⎩,则10a b +=.【解答】解:(1)原式2011201111(8)()()88=---, 201111[8()]()88=-⨯-⨯-, 11()8=⨯-,18=-;(2)原式538()[()]()a b a b a b =---=--.【解答】解:(1)原式3216a a ++==;(2)原式200820085655()()()6566=-⨯⨯-=-. 【解答】解:原式334[()()]a a a =--,37()a a =-,10a =-.【解答】解:53134()()n n x x x x --+-3434n n x x ++=-+0=.【解答】解:原式235()()x x x x x =----66x x =+62x =.【解答】解:23()()x y x y --23()x y +=-5()x y =-.(注:可编辑下载,若有不当之处,请指正,谢谢!)。

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