Simplify completely quantity 8 x minus 56 over quantity x squared minus 49 divided by quantity x minus 6 over quantity x squared plus 11 x plus 28

A. 4 open parentheses x plus 4 close parentheses over quantity x minus 3

B. 8 open parentheses x plus 2 close parentheses over quantity x minus 3

C. 8 open parentheses x plus 4 close parentheses over quantity x minus 7

D. 8 open parentheses x plus 4 close parentheses over quantity x minus 6

Respuesta :

d .........................................

Answer:

Option (D) is correct.

8 open parentheses x plus 4 close parentheses over quantity x minus 6

Step-by-step explanation:

Given : 8 x minus 56 over quantity x squared minus 49 divided by quantity x minus 6 over quantity x squared plus 11 x plus 28

We need to simplify above and choose one correct option out of given options.

First writing each term mathematically,

8 x minus 56 over quantity x squared minus 49 is written as , [tex]\frac{8x-56}{x^2-49}[/tex]

quantity x minus 6 over quantity x squared plus 11 x plus 28 is written as,

[tex]\frac{x-6}{x^2+11x+28}[/tex]

Combining, we get,  8 x minus 56 over quantity x squared minus 49 divided by quantity x minus 6 over quantity x squared plus 11 x plus 28 as

[tex]\frac{8x-56}{x^2-49}\div \frac{x-6}{x^2+11x+28}[/tex]

Solving fraction separately, we get,

Consider first expression,

Applying identity [tex]a^2-b^2=(a+b)(a-b)[/tex]

[tex]\Rightarrow \frac{8x-56}{x^2-49}=\frac{8x-56}{(x+7)(x-7)}[/tex]

taking 8 common from numerator,

[tex]\Rightarrow \frac{8x-56}{(x+7)(x-7)}=\frac{8(x-7)}{(x+7)(x-7)}[/tex]

On simplifying , we get,

[tex]\Rightarrow \frac{8(x-7)}{(x+7)(x-7)}=\frac{8}{(x+7)}[/tex]

Consider second expression,  [tex]\frac{x-6}{x^2+11x+28}[/tex]

Solving quadratic using middle term splitting method,

[tex]\Rightarrow \frac{x-6}{x^2+11x+28}=\frac{x-6}{x^2+7x+4x+28}[/tex]

[tex]\Rightarrow \frac{x-6}{x^2+7x+4x+28}= \frac{x-6}{(x+4)(x+7)}[/tex]

Combining,

[tex]\frac{8x-56}{x^2-49}\div \frac{x-6}{x^2+11x+28}[/tex]

[tex]\Rightarrow \frac{8}{(x+7)}\div \frac{x-6}{(x+4)(x+7)}[/tex]

[tex]\Rightarrow \frac{8}{(x+7)}\times \frac{(x+4)(x+7)}{x-6}[/tex]

On solving,

[tex]\Rightarrow 8 \times \frac{(x+4)}{x-6}[/tex]

Thus, we obtain (D) is as correct option.

8 open parentheses x plus 4 close parentheses over quantity x minus 6