14.1.1 《同底数幂的乘法》练习题例1.计算:(1) x2∙ x5 (2)2m∙2n (3)(−2)3×(−2)2 (4)xm∙ x3m+1 练一练(一)1.下列计算正确的是( ) A.a2∙a3=a6 B.x3∙ x3=2 x3 C.y5+ y5=y10 D.b2∙b=b32.计算x3∙ x2结果正确的是( ) A.−x6 B. x6 C. x5 D. −x53. 计算:(1)b5∙b (2)a2∙a6 (3) y2n∙ yn+1练一练(二)(1) (x+ y )2(x+ y)4 (2) (a−b)2m(a−b)m−1练一练(三)计算:(1)10×104×108 (2)m ∙m2∙m3 (3)(−12 )×(−12 )2×(−12 )3练一练(四)1.m16可以写成( ) A. m8+m8 B. m8∙m8 C. m2∙m8 D.m4∙m42. 已知a x =4,a y =8,则a x + y的值为 .3.已知3x=2,则3x+2=¿ .4.已知27×32=3x,则x=¿ .5.已知:5y +2=a,则5y=¿ .