One-dimensional linear equation:

There is only one unknown, and the highest degree of unknown is once.

For example: 3x+3 = 6 = > 3x = 6-3 = > x = (6-3)/3 =1

One-variable quadratic equation:

There is only one unknown, and the highest number of unknowns is quadratic.

For example, the square of x +2x-3 =0.

X= 1 or x=-3 can be obtained by cross multiplication or directly setting the formula.

Binary linear equation:

An equation has two unknowns, and the highest degree of the two unknowns is one.

For example, 2x+3y=9.

Only one equation of binary linear equation can't be solved, and it takes two equations to be solved ~

Binary quadratic equation:

An equation with two unknowns whose highest degree is quadratic ~

For example, the square of x+the square of y =23.

Only one equation of binary quadratic equation can't be solved, and two equations may not be solved ~