Question

Is the expression `2y-5+3y^2` a polynomial?

Answer 1

It's a trinomial.

Explanation:

It can be expressed as `3y^2 + 2y^1 - 5y^0` which has 3 terms. polynomials are expressions with more than 3 terms when written in descending powers.
Example: `x^5 + 2x^4 -0x^3 +0x^2 +0x^1 +0x^0` would not be a binomial, because it has more than two terms when written in descending powers and using zero coefficients.