Math 20 points Only real answers pleaaase! Please don't answer with just a picture because I won't be able to see it.

Step-by-step explanation:

Polynomials are closed under an operation if it produces a polynomial.

5x⁴, x² + 2x + 1 and x³ - 10x³ + 28x - 15

are all polynomials of x.

x - 3 + (-3)/(x - 2) is not a polynomial because x can be found in the denominator of a fractional term.

The answer is Option A.

a and b are equal

step-by-step explanation:

-362

step-by-step explanation:

(12)(4)+2(12)-34(12)+2(12)-3

  \/         \/         \/         \/

  48 +   24 -   408 + 24 - 3

      \   /               \   /

          72     -     432 - 3 = -363