Which of the following statements best describes the Khmer Empire?
A. It was a nomadic empire that inhabited Mesopotamia about 3,000 years ago.
B. It was an advanced civilization that developed in South America around 100 CE.
It developed the world's largest pre-industrial city between 800 and 1431 CE.
D. It was an empire of nomads who roamed the grasslands of northern Asia.

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].

Ithink is a i believe