Hi Betty,

The terms trinomial, binomial and monomial refer to the number of unlike terms. "tri" indicates 3, "bi" indicates 2 and "mono" indicates 1. For example

$4x^2 + 3x -2$ is a trinomial
$5x - 2x^3$ is a binomial and
$4 - 2x^2 + 5x^4$ is a trinomial.

However $3x - 5x^2 + x$ has three terms but when you collect like terms the expression becomes $4x - 5x^2$ so it is a binomial.

The terms linear, quadratic, cubic, quartic and so on indicate the highest power of the variable. So for my three examples

$4x^2 + 3x -2$ is a quadratic
$5x - 2x^3$ is a cubic and
$4 - 2x^2 + 5x^4$ is a quartic.

Write back if you need more assistance.

Penny