IDNLearn.com is designed to help you find accurate answers with ease. Discover trustworthy solutions to your questions quickly and accurately with help from our dedicated community of experts.

Type the correct answer in the box.

Consider the expressions below:
A. [tex]$\quad 11x^2 + 6x - 6$[/tex]
B. [tex]$7x^2 + 16x + 25$[/tex]
C. [tex]$\quad 11x^2 - 5x + 13$[/tex]
D. [tex]$7x^2 - 3x + 8$[/tex]

For each expression below, select the letter that corresponds to the equivalent expression given above.

1. [tex]$\left(x^2 + 15x + 65\right) + (2x - 5)(3x + 8)$[/tex] is equivalent to expression [tex]$\square$[/tex]
2. [tex]$(4x + 1)(3x - 4) - \left(5x^2 - 10x - 12\right)$[/tex] is equivalent to expression [tex]$\square$[/tex]
3. [tex]$\left(8x^2 + 19x + 4\right) + (3x + 2)(x - 5)$[/tex] is equivalent to expression [tex]$\square$[/tex]
4. [tex]$(6x + 1)(3x - 7) - \left(7x^2 - 34x - 20\right)$[/tex] is equivalent to expression [tex]$\square$[/tex]


Sagot :

To find which expressions correspond to the given options A, B, C, and D, we need to expand and simplify each expression step by step.

1. Expression: [tex]\((x^2 + 15x + 65) + (2x - 5)(3x + 8)\)[/tex]

First, expand [tex]\((2x - 5)(3x + 8)\)[/tex]:
[tex]\[ (2x - 5)(3x + 8) = 2x \cdot 3x + 2x \cdot 8 - 5 \cdot 3x - 5 \cdot 8 = 6x^2 + 16x - 15x - 40 = 6x^2 + x - 40 \][/tex]

Now, add this result to [tex]\(x^2 + 15x + 65\)[/tex]:
[tex]\[ x^2 + 15x + 65 + 6x^2 + x - 40 = 7x^2 + 16x + 25 \][/tex]

The equivalent expression is B.

2. Expression: [tex]\((4x + 1)(3x - 4) - (5x^2 - 10x - 12)\)[/tex]

First, expand [tex]\((4x + 1)(3x - 4)\)[/tex]:
[tex]\[ (4x + 1)(3x - 4) = 4x \cdot 3x + 4x \cdot (-4) + 1 \cdot 3x + 1 \cdot (-4) = 12x^2 - 16x + 3x - 4 = 12x^2 - 13x - 4 \][/tex]

Now, subtract [tex]\(5x^2 - 10x - 12\)[/tex] from this result:
[tex]\[ 12x^2 - 13x - 4 - 5x^2 + 10x + 12 = 7x^2 - 3x + 8 \][/tex]

The equivalent expression is D.

3. Expression: [tex]\((8x^2 + 19x + 4) + (3x + 2)(x - 5)\)[/tex]

First, expand [tex]\((3x + 2)(x - 5)\)[/tex]:
[tex]\[ (3x + 2)(x - 5) = 3x \cdot x + 3x \cdot (-5) + 2 \cdot x + 2 \cdot (-5) = 3x^2 - 15x + 2x - 10 = 3x^2 - 13x - 10 \][/tex]

Now, add this result to [tex]\(8x^2 + 19x + 4\)[/tex]:
[tex]\[ 8x^2 + 19x + 4 + 3x^2 - 13x - 10 = 11x^2 + 6x - 6 \][/tex]

The equivalent expression is A.

4. Expression: [tex]\((6x + 1)(3x - 7) - (7x^2 - 34x - 20)\)[/tex]

First, expand [tex]\((6x + 1)(3x - 7)\)[/tex]:
[tex]\[ (6x + 1)(3x - 7) = 6x \cdot 3x + 6x \cdot (-7) + 1 \cdot 3x + 1 \cdot (-7) = 18x^2 - 42x + 3x - 7 = 18x^2 - 39x - 7 \][/tex]

Now, subtract [tex]\(7x^2 - 34x - 20\)[/tex] from this result:
[tex]\[ 18x^2 - 39x - 7 - 7x^2 + 34x + 20 = 11x^2 - 5x + 13 \][/tex]

The equivalent expression is C.

Final Answer:

[tex]\[ \begin{align*} (x^2 + 15x + 65) + (2x - 5)(3x + 8) & \text{ is equivalent to expression } \boxed{B} \\ (4x + 1)(3x - 4) - (5x^2 - 10x - 12) & \text{ is equivalent to expression } \boxed{D} \\ (8x^2 + 19x + 4) + (3x + 2)(x - 5) & \text{ is equivalent to expression } \boxed{A} \\ (6x + 1)(3x - 7) - (7x^2 - 34x - 20) & \text{ is equivalent to expression } \boxed{C} \\ \end{align*} \][/tex]