If logx 5 32 then x 23 32 1125 125 none of these If loga 2x
If log_x 5= 3/2 then x= 2/3 3/2 1/125 125 none of these If log_a 2=x and log_a 3=y then log_a 12= x+2y x-2y 2x-y 2x+y 2xy For a > 0 and b > 0, log a/b= log a/log b log a+ log b log a - log b log b - log a b log a
Solution
Q. 2 If logx 5 = 3/2 , then 5 = x3/2 so that 52/3 = (x3/2)2/3 = x3/2*2/3 = x. Thus, x =52/3. The 1st option is the correct answer.
Q. 7 If loga2 = x , then loga 4 = loga 22 = 2loga 2 = 2x. Also, loga 3 = y, so that loga12 = loga 4*3 = loga 4+ loga 3 = 2x+y. Thus, loga12 = 2x+y ( as log mn = n log m and log (mn) = log m +log n).The 4th option is the correct answer.
Q. 4 For a > 0 and b > 0, log (a/b) = log a – log b ( by the properties of logarithmic operations).The 3rd option is the correct answer.
