Answered

Select the correct answer.

Which expression is equivalent to [tex]\frac{2d-6}{d^2+2d-48} \div \frac{d-3}{2d+16}[/tex] if no denominator equals zero?

A. [tex]\frac{d-3}{d-6}[/tex]
B. [tex]\frac{4}{d-6}[/tex]
C. [tex]\frac{4}{d+8}[/tex]
D. [tex]\frac{2(d+8)}{d-3}[/tex]



Answer :

To determine which expression is equivalent to [tex]\(\frac{2d - 6}{d^2 + 2d - 48} \div \frac{d - 3}{2d + 16}\)[/tex] if no denominator equals zero, we can simplify the given expression through a series of algebraic steps.

First, let's rewrite the division as multiplication by the reciprocal:

[tex]\[ \frac{2d - 6}{d^2 + 2d - 48} \div \frac{d - 3}{2d + 16} = \frac{2d - 6}{d^2 + 2d - 48} \cdot \frac{2d + 16}{d - 3} \][/tex]

Next, simplify the expression [tex]\(\frac{2d - 6}{d^2 + 2d - 48}\)[/tex].

Notice that [tex]\(2d - 6\)[/tex] can be factored:

[tex]\[ 2d - 6 = 2(d - 3) \][/tex]

Now factor [tex]\(d^2 + 2d - 48\)[/tex]. This expression can be factored using the method of factoring quadratic trinomials:

[tex]\[ d^2 + 2d - 48 = (d + 8)(d - 6) \][/tex]

Putting it all together, we get:

[tex]\[ \frac{2(d - 3)}{(d + 8)(d - 6)} \][/tex]

Now consider the expression [tex]\(\frac{2(d - 3)}{(d + 8)(d - 6)} \cdot \frac{2d + 16}{d - 3}\)[/tex].

Notice that [tex]\(2d + 16\)[/tex] can be factored:

[tex]\[ 2d + 16 = 2(d + 8) \][/tex]

So the product becomes:

[tex]\[ \frac{2(d - 3)}{(d + 8)(d - 6)} \cdot \frac{2(d + 8)}{d - 3} \][/tex]

Next, cancel the common factors in the numerator and the denominator:

[tex]\[ \frac{2(d - 3)}{(d + 8)(d - 6)} \cdot \frac{2(d + 8)}{d - 3} = \frac{2(d - 3) \cdot 2(d + 8)}{(d + 8)(d - 6) \cdot (d - 3)} \][/tex]

[tex]\[ = \frac{4(d + 8)}{(d - 6) \cdot (d + 8)} \][/tex]

Cancel the [tex]\((d + 8)\)[/tex] from the numerator and the denominator:

[tex]\[ = \frac{4}{d - 6} \][/tex]

Thus, the equivalent expression is:

[tex]\[ \boxed{\frac{4}{d - 6}} \][/tex]

Therefore, the correct answer is:

B. [tex]\(\frac{4}{d - 6}\)[/tex]