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若x1满足3x+3x=2,x2满足3x+3log3(x-1)=2,则x1+x2=()A.43B.53C.72D.452

题目详情

若x1满足3x+3x=2,x2满足3x+3log3(x-1)=2,则x1+x2=(  )

A.

4
3

B.

5
3

C.

7
2

D. 4

5
2

▼优质解答
答案和解析
∵x1满足3x+3x=2,x2满足3x+3log3(x-1)=2,
3x1-1=
2
3
-x1=-
1
3
-(x1-1),log3(x2-1)=
2
3
-x2=-
1
3
-(x2-1).
∴x1-1+x2-1=-
1
3

化为x1+x2=
5
3

故选:B.