creating a binary search tree (manual)
The property that makes a binary tree a binary search tree is that for every branch labeled $x$, all of the labels in the left subtree are smaller than $x$ and all of the labels in the right subtree are greater than $x$.

If you look at your tree, that property is violated in many places. For example, $5$ is in the right subtree of the node labeled $15$, yet $15 \not &lt; 5$.