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

Question

若x₁满足3x+3^x=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)

Answer 1

∵x₁满足3x+3^x=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．