mam/sir it is c - a not c-d... reply..

Asked by nikitakoolkarni | 24th Sep, 2010, 09:56: AM

Expert Answer:

Dear student

Logab =4  means a4=b

and logcd =2  means c2=d

given b-d =7 so a4-c2 =b-d=7

so (a-c)(a+c)(a2+c)=7

a and c are positive since log is not defined for negative values

So (a+c) and (a2+c) are positive

since  (a-c)(a+c)(a2+c) is positive  so a-c >0

So, c-a < 0  so option b is the correct answer

Answered by  | 24th Sep, 2010, 11:07: AM

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