1.31 is right.

1.26: The question asks for the product of the positive roots of $x$.  Well, all roots of $x$ are positive.  The equation you have is $$2y^2 - 4y + 1 = 0,$$ where $y=\log_{2000}x$.

There are two roots for $y$, which means there are two roots for $x$ as well.  By Vieta's formula, $y_1 + y_2 = 4/2 = 2$.  So it means $$\log_{2000}x_1 + \log_{2000} x_2 = 2.$$  This is the same as $$\log_{2000}(x_1x_2)=2,$$  So $$x_1x_2 = 2000^2=4000000.$$