Understanding and Operating with Polynomials Practice Test

Add the polynomials (combine like terms). The sum should be a polynomial by closure under addition:

$$(4x^3-2x^2+6)+(-x^3+5x-9).$$

Add the polynomials (combine like terms). This illustrates the closure property because the sum of two polynomials is also a polynomial:

$$(2x^4-3x^3+x^2-5)+(x^4+2x^3-4x^2+x+3).$$​