sum of roots

The sum of roots of the equation
x + 1 - 2 log2 (2x + 3) + 2 log4 (10 - 2-x) = 0 is

a) log211
b) log212
c) log213
d) log214

5 Answers

262
Aditya Bhutra ·

i am getting a)

1
rancho6 ·

how? please give detailed sol.

21
mohit_ sharma ·

x+1 - 4log4(2x+3)+2log4(10-2-x)=0
this gives
2-(x+1) = (10-2-x)/(2x+3)2
→ 22x -14.2x + 11=0
put 2x =t
this gives 2x =7± √38
x= log2(7±√38)
thus x1 + x2 =log211

21
mohit_ sharma ·

so ans should be (a)

1
fahadnasir nasir ·

a

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