Why does a year consist of 365 days and a day of 24 hours?

The reason why the year consists of 365 days is because it takes 365 days for our planet to make one full revolution around the sun and the reason why the day consists of 24 hours is because it takes 24 hours for our planet to make one full rotation.  

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].