Question

Which of the following shows that polynomials are closed under subtraction when polynomial 5x − 6 is subtracted from 3x2 − 6x + 2?
answers:
3x2 − 11x + 8 may or may not be a polynomial
3x2 − 11x + 8 will be a polynomial
3x2 − x + 4 may or may not be a polynomial
3x2 − x + 4 will be a polynomial

Answer 1

The correct answer is that 3x²-11x+8 will be a polynomial.

Explanation:
When we subtract polynomials, we combine like terms:
3x² is the only x² term we have.
We have -6x and subtract 5x from it; this gives us -11x.
We have 2 and subtract -6 from it; when we subtract a negative, we add the opposite, which means we have 2--6=2+6=8.

This gives us 3x²-11x+8. This is a polynomial, since it is made of monomials (none of the terms have a negative exponent or a radical sign).

Answer 2

Answer:

option (b) is correct.

we get a polynomial $3x^2-11x+8$

Step-by-step explanation:

Given :  Polynomial 5x -6 and $3x^2-6x+2$.

We have to choose out of given options which shows that polynomials are closed under subtraction when polynomial 5x − 6 is subtracted from  $3x^2-6x+2$.

We first subtract the polynomial

$\Rightarrow 3x^2-6x+2-(5x-6))$

$\Rightarrow 3x^2-6x+2-5x+6$

similar terms are terms having same variables with same degree.

Here,  -6x and -5x are similar

and 2 and 6 are similar.

Adding similar terms, we get,

$\Rightarrow 3x^2-11x+8$

Polynomial is an algebraic expression that can involves variables with non negative integer terms and constants.

Thus, we get a polynomial $3x^2-11x+8$

Hence, option (b) is correct.