plzzz solve it fast no. 31 in the following image through logarithm
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Given that,
P=log20......................1
Q=log25.....................2
Also given that,
2log(x+1)=2P-Q
By putting eq1 and eq2 in above equation we get,
2log(x+1)=2(log20)-log25
log(x+1)²=2{log5+log4}-log5²
log(x+1)²=2log5+2log4-2log5
log(x+1)²=log2⁴
Removing log from both sides we get,
(x+1)²=2⁴
x+1=2²
x+1=4
x=3
Hence value of x=3.
P=log20......................1
Q=log25.....................2
Also given that,
2log(x+1)=2P-Q
By putting eq1 and eq2 in above equation we get,
2log(x+1)=2(log20)-log25
log(x+1)²=2{log5+log4}-log5²
log(x+1)²=2log5+2log4-2log5
log(x+1)²=log2⁴
Removing log from both sides we get,
(x+1)²=2⁴
x+1=2²
x+1=4
x=3
Hence value of x=3.
hrik21:
plzz explain ur 11th line
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by using properties of logarithm we can solve this problem...
see attachment. .
here x = 3 is the solution
but x = -5 is not the solution of given equation... because argument of log never be negative..
___________________________
hope it will help u
see attachment. .
here x = 3 is the solution
but x = -5 is not the solution of given equation... because argument of log never be negative..
___________________________
hope it will help u
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