Question

Express in simplest form: x2+8x−48x2−144 ÷(4−x) (1 point)
Responses

−(x+4)(x−4)(x+12)
the fraction with numerator negative open paren x plus 4 close paren and denominator open paren x minus 4 close paren times open paren x plus 12 close paren

(x−4)(x+4)x−12
the fraction with numerator open paren x minus 4 close paren times open paren x plus 4 close paren and denominator x minus 12

−1x−12
the fraction with numerator negative 1 and denominator x minus 12

1x−12

Answers

GPT-4o mini
To simplify the expression \((x^2 + 8x - 48)(x^2 - 144) \div (4 - x)\), we will follow these steps:

1. Factor each part of the expression.
2. Rewrite the expression using the factored form.
3. Simplify the resulting expression.

### Step 1: Factor the expressions

**Factor \(x^2 + 8x - 48\):**
To factor \(x^2 + 8x - 48\), we need to find two numbers that add to \(8\) and multiply to \(-48\). These two numbers are \(12\) and \(-4\).

So,
\[
x^2 + 8x - 48 = (x + 12)(x - 4)
\]

**Factor \(x^2 - 144\) (a difference of squares):**
\[
x^2 - 144 = (x - 12)(x + 12)
\]

### Step 2: Rewrite the entire expression:

Now substitute the factored forms into the original expression:
\[
\frac{(x + 12)(x - 4)(x - 12)(x + 12)}{4 - x}
\]

Note that \(4 - x = -(x - 4)\), so we can rewrite the expression as:
\[
\frac{(x + 12)(x - 4)(x - 12)(x + 12)}{-(x - 4)}
\]

### Step 3: Simplify the expression:

Cancel out the \((x - 4)\) terms:
\[
= - (x + 12)(x + 12)(x - 12)
\]
\[
= - (x + 12)^2 (x - 12)
\]

### Final Result:

The expression in the simplest form is:
\[
-(x + 12)(x + 12)(x - 12)
\]

### Similar Form:

Now, based on the responses provided in the question, it looks like the equivalent simplest form could match any of the given options. The first one is:
\[
-(x + 4)(x - 4)(x + 12)
\]
This is not the correct answer.

The second one is:
\[
(x - 4)(x + 4)x - 12
\]
Also not correct.

The third one is:
\[
-\frac{1}{x - 12}
\]
This seems incorrect because we still have the factor.

The fourth one is:
\[
\frac{1}{x - 12}
\]
which does not match our expression.

Therefore, from the responses provided, we can conclude:
None of the suggested forms are matching the simplified expression.

The correct answer should be \( - (x + 12)^2 (x - 12) \), and it appears to not be listed among the choices.

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