Question

If `7^(logx)+x^(log7) = 98`, then `log_(10)sqrt(x)`, then `(a)/(b) + (b)/(a) =`
A. 47
B. 51
C. 14
D. 49

Answer 1

Correct Answer - B
(i) Use log a + log b = log ab and remove logarithms on both the sides and evaluate `(a-b)^(2)`.
(ii) Express RHS into single logarithm with coeficient 1.
(iii) Apply antilog and cancel the logarithms on both sides.
(iv) Divide LHS and RHS by ab and obtain the required value.