Which of the following expressions is equivalent to

[tex]\[ (x+7)\left(x^2-3x+2\right)? \][/tex]

A. [tex]\[ x^3-3x^2+2x+14 \][/tex]
B. [tex]\[ x^3+4x^2-19x+14 \][/tex]
C. [tex]\[ x^3-3x+14 \][/tex]
D. [tex]\[ x^2-2x+9 \][/tex]



Answer :

To determine which of the provided expressions is equivalent to [tex]\((x+7)\left(x^2-3x+2\right)\)[/tex], we should expand and simplify the given expression step by step.

Given expression:
[tex]\[ (x+7)(x^2 - 3x + 2) \][/tex]

We will use the distributive property (also known as the FOIL method for binomials) to expand the expression:

1. Distribute [tex]\(x\)[/tex] from [tex]\( (x + 7) \)[/tex] to each term in [tex]\( (x^2 - 3x + 2) \)[/tex]:

[tex]\[ x \cdot x^2 + x \cdot (-3x) + x \cdot 2 = x^3 - 3x^2 + 2x \][/tex]

2. Distribute [tex]\(7\)[/tex] from [tex]\( (x + 7) \)[/tex] to each term in [tex]\( (x^2 - 3x + 2) \)[/tex]:

[tex]\[ 7 \cdot x^2 + 7 \cdot (-3x) + 7 \cdot 2 = 7x^2 - 21x + 14 \][/tex]

3. Combine the results from both distributions:

[tex]\[ (x^3 - 3x^2 + 2x) + (7x^2 - 21x + 14) \][/tex]

4. Combine like terms:

[tex]\[ x^3 + (-3x^2 + 7x^2) + (2x - 21x) + 14 \][/tex]

[tex]\[ x^3 + 4x^2 - 19x + 14 \][/tex]

Through this step-by-step expansion and simplification, we determine that the expression [tex]\((x + 7)(x^2 - 3x + 2)\)[/tex] is equivalent to:

[tex]\[ x^3 + 4x^2 - 19x + 14 \][/tex]

Therefore, the correct answer is:

[tex]\[ \boxed{B. \, x^3 + 4 x^2 - 19 x + 14} \][/tex]