Linear Equations in Two Variables

Equations are mathematical statements containing two algebraic expressions on both sides of an 'equal to (=)' sign.

For example, 3x + 5 = 15.

Equal to

L.H.S (left hand side) = R.H.S (right hand side)

Equations can be solved to find the value of an unknown variable representing an unknown quantity.

No equal to

It means it is not an equation.

It will be considered as an expression.

Equation vs Expression

Parts of an Equation

Term: A group of numbers, letters and brackets multiplied together.

such as "(4 x 2)" or "8x."

Expression: A term or several terms that you add or subtract.

such as "(4 x 2) + 3x - 4."

Variable: A symbol representing a number that can change in value.

For example, in the term "5x," "x" is the variable.

Constant: a number with a fixed and unchangeable value.

Coefficient: a number in front of a variable.

For example, in the term "12y," "12" is the coefficient.

Symbol: a mark or sign that stands for something else.

For example, the plus symbol means to add.

Exponent: An exponent tells you how many times a number multiplies by itself.

Polynomial: An algebraic expression which has two or more algebraic terms.

"poly" means "many"

"nomial" means "terms"

Quotient: the solution of one number divided by another.

For example, the quotient of "200 / 20" is "10."

Linear equation in two variables

An equation contains two variables and the degree of each term containing one variable.

General form

Rules

(1) Two variables

(2) Degree 1

(3) A,B are not equal to zero at the same time.