第2课时 幂的乘方与积的乘方(1)
【基础巩固】
1.下列计算正确的是 ( )
A.x3.x2=2x6 B.x4.x2=x8 C.(-x2)3=-x6 D.(x3)2=x5 2.下列运算正确的是 ( )
A.x3.x2=x5 B.(x3)3=x6 C.x5+x5=x10 D.x6-x3=x3
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3.(1)①????=_______,②(a5)6=_______,③[(-8)3]2=_______;
???3???
(2)①(x3)2n=_______,②(a2)n.a3=_______,③(a2)4.(-a)3=_______;
(3)①x12=( )6=( )4=( )3=( )2,②(a2)( ).a3=a11. 4.(1)若ax=2,则a3x=_______;
(2)若a、b为正整数,且3a.9b=81,则a+2b=_______. 5.已知:2+
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443322aa=22×,3+=32×,4+=42×……若10+=102×(a、b为33bb151588正整数),则a+b=_______.
6.计算:
(1)(103)5 (2)[(-a)3]2 (3)[(x2)3]7;
(4)(-a3)2.(-a2)3; (5)(a2)n.(a3)2n; (6)27a·3b;
(7)(x2)n-(xn)2; (8)a2.a4+(-a2)3; (9)(a2)3-a3.a3+2(a3)2.
【拓展提优】
7.下列运算正确的是 ( )
A.-a4.a3=a7 B.a4.a3=a12 C.(a4)3=a12 D.a4+a3=a7
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8.(-ak1)2等于 ( )
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A.-a2k1 B.a2k2 C.a2k2 D.2ak1 9.(2012.苏州)若3×9m×27m=311,则m的值为 ( ) A.2 B.3 C.4 D.5 10.(1)(x4)3=_______,(-y2)3=_______,(am)2=_______;
(2)x30=(_______)6=(x3._______)2=[x.(-x3).(_______)3]3. 11.(1)若2a+3b=-2,,则9a.27b的值为_______;
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(2)已知4x=2x3,则x=_______. 12.计算:
(1)(-a2)3.(-a3)4; (2)a4.a4+(-a2)4-3(a4)2;
(3) (-a2)3.a3+4(-a)2.a7-5(a3)3; (4)a5.a7+(-a4)3-2a2.(a2)5+3[(a3)3.a3]
13.求值:
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(1)若xm.x2m=-2,求x9m的值; (2)已知am=-2,an=3,求a3m2n的值.
14.(1)已知m为正整数,且4×8m×16m=48,求m的值;
(2)已知:x=3m-2,y=5+9m,用含x的代数式表示y.
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