Capitals are two straight lines, and lowercase has a little curvature. There is no need to distinguish in the calculation, and the unknown x can be expressed in the junior high school. X' can be omitted, so it is a formal writing method of mathematics, which is very useful for writing math problems. He should pay attention to distinguish it from the Chinese pinyin' X'. Chinese pinyin should not be prominent, and mathematics should generally be prominent.
Mathematical use
Generally, X is used to represent the unknown, which can directly participate in the operation and is widely used in life. Like other letters such as Y and Z, it can sometimes represent all numbers. An equation that two algebraic expressions (such as two numbers, two functions, two quantities and two operations) are equal and contain unknowns is called an equation.
Equations are divided into integral equations and fractional equations. For example, y=a(x-h)? +k(a≠0, a, h and k are constants), and x is an unknown term or quantity.