Question

Plz answer Tomorrow IMO EXAM
25th question

Answer 1

and the answer is 25

Answer 2

Option ( c ) is correct.

Explanation :

Given

log (x-y) - log5 -(1/2)logx-(1/2)logy=0

multiply each term by 2 , we get

=> 2log(x-y) - 2log5 - logx - log y = 0

=> 2 log(x-y) = 2log5+logx+logy

=> log(x-y)² = log5² + logx + logy

=> log(x-y)² = log ( 5²xy )

=> ( x - y )² = 25xy

=> x² - 2xy + y² = 25xy

=> x² + y² = 25xy + 2xy

=> x² + y² = 27xy

Divide each term by xy, we get

=> x²/xy + y²/xy = 27xy/xy

=> x/y + y/x = 27

•••••

=>