An factor of an integer is another integer that divides into it evenly. For example, \(2\) is a factor of \(12\), since

Numbers can have many different factors, both positive and negative. For example, the factors of \(15\) are \(\{1,3,5,15,-1,-3,-5,15\}\) because

• \(1 \times 15 = 15 \) and \(3 \times 5 = 15\)
• \(-1 \times -15 = 15\) and \(-3 \times -5 = 15\)

A factor of an algebraic expression is an algebraic expression that can be multiplied by another algebraic expression to give the original expresion.

For example, \((x + 2)\) and \((x + 3)\) are factors of the algebraic expression \(x^2 + 5x + 6\).