The larger number is x/2 and the larger number is x. We are told that the product of x and x/2 is 450.
x(x/2)=450
(x^2)/2=450
x^2=900
x=√900
x=±30
We were not told that the numbers must be positive so there are two solutions. The larger number is either -30 or +30.
check...
-30(-15)=450 and 30(15)=450