Answer 1

Binary tree is a finite set of elements called nodes such that is :
1). It may be empty or
2). It is partitioned into three disjoint subsets :
(a) there is a single distinguished element called the root of tree. (b) other two subsets are themselves binary tree called left subtree and right subtree of the original tree.
B = (3R -5T)² - (R + Q³)