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lg25+2/3lg8+lg5*lg20+(lg2)^2=?

原式=2lg5+2lg2 +lg5(lg5+2lg2)+(lg2)^2 =2(lg5+lg2)+(lg2)^2+2lg2lg5+(lg5)^2 =2lg10+[lg2+lg5]^2 =2+1^2 =2+1 =3

lg5^2+2/3lg8+lg5*lg20+(lg2)^2 =2lg5+2/3lg2^3+lg5*lg5*2^2 +(lg2)^2 =2lg5+2/3 * 3 lg2+lg5(lg5+2lg2)+(lg2)^2 =2lg5+2lg2+(lg5)^2+2lg5lg2+(lg2)^2 =2(lg5+lg2)+(lg5)^2+2lg5lg2+(lg2)^2 =2lg10 + (lg5+lg2)^2 =2+(lg10)^2 =2+1=3

lg5^2+2/3lg8+lg5*lg20+(lg2)^2 =2lg5+2lg2+lg5*(1+lg2)+(lg2)^2 =2(lg5+lg2)+lg5+lg5lg2+(lg2)^2 =2+lg5+(lg5+lg2)lg2 =2+lg5+lg2 =2+1 =3

(1)原式=7?33?333×8?6?1333+431+13=7?33?633?233+4343=?33+33=0 (2)原式=(lg?2)2+43log?10223+lg?5?(lg?4+lg?5)+lg?52=(lg?2)2+2lg?2+2lg?5?lg?2+(lg?5)2+2lg?5=(lg?2+lg?5)2+2(lg?2+lg?5)=1+2=3.

(lg5)2+2/3lg8+lg5*lg20+(lg2)2 =(lg5)2+2lg2+lg5(lg5+2lg2)+(lg2)2 =(lg5)2+2lg5lg2+(lg2)2+2lg2+(lg5)2 =(lg5+lg2)2+2lg2+(lg5)2 =1+lg100lg2+(lg5)2 =1+(2lg5+lg2)lg2+(lg5)2 =1+(lg2)2+2lg5lg2+(lg5)2 =1+(lg2+lg5)2 =1+1 =2

(1)原式=sin60°?cos30°+sin30°?cos60°=sin(30 0 +60 0 )=sin90°=1.(2)原式=2lg5+2lg2+lg5?(2lg2+lg5)+lg2?lg2=2+(lg5) 2 +2lg2?lg5+(lg2) 2 =2+(lg5+lg2) 2 =3. (3)原式= 2? 3 1 2 ? 3 1 3 ? 2 - 1 3 ? 3 1 6 ? 2 1 3 = 2 1-...

(1)∵x+y=12,xy=9,且x>y,∴x12?y12x12+y12>0且(x12?y12x12+y12)2=x+y?2(xy)12x+y+2(xy)12=12?612+6=13∴x12?y12x12+y12=33,(2)lg25+23lg8+lg5?lg20+(lg2)2=lg25+lg4+lg5?lg20+(lg2)2=2+(1-lg2)?(1+lg2)+(lg2)2=2+1=3

lg25+2\3lg8+lg5*lg20+(lg2)² =lg25+lg4+lg5*lg4*5+(lg2)² =lg100+lg5*(lg4+lg5)+(lg2)² =2+2*lg5*lg2+(lg5)²+(lg2)² =2+(lg5+lg2)² =2+1 =3

(1)lg25+23lg8+lg5lg20+(lg2)2=lg25+lg4+lg5(2lg2+lg5)+(lg2)2=lg100+2lg5lg2+(lg5)2+(lg2)2=2+(lg2+lg5)2=3;(2)∵12log8a+log4b=52,log8b+log4a2=7,∴log64a+log64b3=52,log64b2+log64a6=7,∴ab3=6452=85,b2a6=647,即a3...

1、数形结合法很简单。画出y=2^x的图像,向下平移1个单位,刚好交x轴于原点(0,0),此时渐近线为y=-1。再将x0)或向上移-a个单位(a

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