Using complete sentences, explain three features that make lake baikal one of the most unique lakes in the world.

Lake Baikal is a lake that has lots of specific features, but it is best know for:
- It is estimated that it is the oldest lake in the world (25-30 million years)
- It is one of the lakes that has the clearest water
- It is the world's deepest lake (1642 m)

Amath expression is a collection of one or more terms, which are separated by the signs ( + , - , x , / ).example :   8+b8+b  or  a−3a−3in algebra, an equation is a mathematical statement with two expressions where, each expression is separated by an equal (=) sign. variables can be present on both the sides of the equality (=) sign and we use letters to denote such variables.example 1:   x=4+2x=4+2  , [here, we can observe that the variable is present only on one side of the equation].example 2:   2x+3=x+42x+3=x+4  , [here, we can observe that the variables are present on both side of the equation].