2.5的X次方等于1000,0.25的Y次方等于10002.5^x=10000.25^y=1000xlg2.5=lg1000x=3/lg2.51/x=lg2.5/3ylg0.25=lg1000y=3/lg0.251/y=lg0.25/31/x-1/y=lg2.5/3-lg0.25/3 =lg10/3 =1/3