if log10(x)=3+log10(y), find xy.
Let x and b be positive real numbers so that logb(x2)=10 Find log3√b(1x)
so i've been stuck on these problems.... im pretty sure we apply some log formula to it but im not sure what.
help appreciated!
thank you!!
+37167 I think this is how to do this one:
logb (x^2) = 10
2 logb (x) = 10
logb (x) = 5
Now use the log base-change rule for the second part ( to change to base 'b' )
= logb (1/x) / logb ( b1/3)
= logb (x-1) / ( 1/3 logb (b) ) remember logb (b) = 1
= (-1) logb (x) / (1/3)
= -3 logb(x) = - 3 ( 5) = -15
