Denominator : The denominator of a fraction $\frac{a}{b}$ is the number $b$ below the fraction bar.

Equation : An equation is a mathematical statement in which two expressions are written with an equal sign in between. A solution of an equation is a set of variables that makes the statement a true statement.

Multiplication : Multiplication is the mathematical operation that is a shorthand for adding the same amount several times. For example $3\cdot 4=4+4+4=12.$

Numerator : The numerator of a fraction $\frac{a}{b}$ is the number $a$ above the fraction bar.

Polynomial expansion : Polynomial expansion refers to multiplying out brackets in a factorization of a polynomial. The most commonly used polynomial expansions are $(x+y)^2=x^2+2xy+y^2,$ $(x-y)^2=x^2-2xy+y^2$ and $(x+y)(x-y)=x^2-y^2.$

Square root : The square root of $x$ denoted by $\sqrt{x}$ is the positive number such that $(\sqrt{x})^2=\sqrt{x}\cdot \sqrt{x}=x.$ For example $\sqrt{9}=3.$

Squared : $x$ squared refers to the number $x^2=x\cdot x.$ For example 3 squared equals 9.