Get expert advice and insights on any topic with IDNLearn.com. Get the information you need from our community of experts, who provide detailed and trustworthy answers.

Consider the polynomials given below.

[tex]\[
\begin{array}{l}
P(x)=x^4+3x^3+2x^2-x+2 \\
Q(x)=\left(x^3+2x^2+3\right)\left(x^2-2\right)
\end{array}
\][/tex]

Determine the operation that results in the simplified expression below.

[tex]\[
x^5 + x^4 - 5x^3 - 3x^2 + x - 8
\][/tex]

A. [tex]\(P-Q\)[/tex]
B. [tex]\(Q-P\)[/tex]
C. [tex]\(P+Q\)[/tex]
D. [tex]\(PQ\)[/tex]


Sagot :

Let's break down the problem and determine which operation on the polynomials [tex]\( P(x) \)[/tex] and [tex]\( Q(x) \)[/tex] results in the given simplified expression.

First, let's rewrite the polynomials:
[tex]\[ P(x) = x^4 + 3x^3 + 2x^2 - x + 2 \][/tex]
[tex]\[ Q(x) = (x^3 + 2x^2 + 3)(x^2 - 2) \][/tex]

Next, we'll expand [tex]\( Q(x) \)[/tex]:
[tex]\[ Q(x) = (x^3 + 2x^2 + 3)(x^2 - 2) \][/tex]
[tex]\[ Q(x) = x^3 \cdot x^2 + x^3 \cdot (-2) + 2x^2 \cdot x^2 + 2x^2 \cdot (-2) + 3 \cdot x^2 + 3 \cdot (-2) \][/tex]
[tex]\[ Q(x) = x^5 - 2x^3 + 2x^4 - 4x^2 + 3x^2 - 6 \][/tex]
[tex]\[ Q(x) = x^5 + 2x^4 - 2x^3 - x^2 - 6 \][/tex]

Now let's examine the given simplified expression:
[tex]\[ x^5 + x^4 - 5x^3 - 3x^2 + x - 8 \][/tex]

We need to compare this expression against the results of performing various operations on [tex]\( P(x) \)[/tex] and [tex]\( Q(x) \)[/tex].

Let's consider each operation one by one.

Operation: [tex]\( P(x) - Q(x) \)[/tex]

[tex]\[ P(x) - Q(x) = \left( x^4 + 3x^3 + 2x^2 - x + 2 \right) - \left( x^5 + 2x^4 - 2x^3 - x^2 - 6 \right) \][/tex]
[tex]\[ P(x) - Q(x) = -x^5 + x^4 + 5x^3 + 3x^2 - x + 8 \][/tex]

Operation: [tex]\( Q(x) - P(x) \)[/tex]

[tex]\[ Q(x) - P(x) = \left( x^5 + 2x^4 - 2x^3 - x^2 - 6 \right) - \left( x^4 + 3x^3 + 2x^2 - x + 2 \right) \][/tex]
[tex]\[ Q(x) - P(x) = x^5 + x^4 - 5x^3 - 3x^2 + x - 8 \][/tex]

Given the comparison, it is clear that the correct operation is:
[tex]\[ Q(x) - P(x) \][/tex]

Thus, the operation that results in the simplified expression:

[tex]\[ x^5 + x^4 - 5x^3 - 3x^2 + x - 8 \][/tex]

is
[tex]\[ \boxed{Q - P} \][/tex]

The answer is:
B. [tex]\( Q - P \)[/tex]