第10练指数与对数[基础保分练]1.(a>0)用分数指数幂表示为________.2.已知x<1,化简-=________.3.(2019·连云港模拟)计算-(π+1)0+,所得结果为________.4.已知3x=4y=6,则+=________.5.(2019·南京调研)已知log7[log3(log2x)]=0,那么=________.6.ln1+log(-1)(-1)=________.7.log2781+log48+2-1+log2=________.8.若a=log92,则9a=________,3a+3-a=________.9.(2018·苏州调研)已知4a=2,logax=2a,则正实数x=________.1242312x213110.若15a=5b=3c=25,则+-=________.[能力提升练]1.[(2+3)2(2-3)2]+8=________.2.(2018·常州模拟)若log2(log3x)=log3(log2y)=2,则x+y=________.3.已知x=log23,则=________.4.(2018·无锡调研)已知函数y=4ax-9-1(a>0且a≠1)恒过定点A(m,n),则logmn=________.5.已知+=3,则a=________.6.(2019·南京模拟)已知常数a>0,函数f(x)=的图象经过点P,Q,若2p+q=16pq,则a=________.13232答案精析基础保分练1.a2.13.4.25.6.17.38.29.10.1能力提升练1.52.5933.解析由x=log23,得2x=3,∴2-x==,23x=(2x)3=33=27,2-3x==,∴==.4.解析令指数x-9=0,则4×a9-9-1=3,据此可得定点的坐标为(9,3),则m=9,n=3,∴logmn=log93=.5.26.4解析函数f(x)=的图象经过点P,Q.则+=-=1,整理得=1,解得2p+q=a2pq,由于2p+q=16pq,所以a2=16,由于a>0,故a=4.7834