## lindseyharrison 3 years ago What is the simplified form of x^2 - 16 / x + 4

1. jim_thompson5910

Hint: x^2 - 16 x^2 - 4^2 (x-4)(x+4)

2. lindseyharrison

x - 4, with the restriction x ≠ 4 x + 4, with the restriction x ≠ - 4 x - 4, with the restriction x ≠ - 4 x + 4, with the restriction x ≠ 4

3. jim_thompson5910

I'm using the difference of squares rule

4. lindseyharrison

@jim_thompson5910 is it A?

5. jim_thompson5910

it is x-4, but the restriction is not x ≠ 4 since 4 is a perfectly valid input in the original expression

6. jim_thompson5910

x+4 = 0 x = -4 is the value that makes the denominator zero, so this is the restricted value

7. lindseyharrison

So it would be C

8. jim_thompson5910

yes, it's C

9. moha_10

@jim_thompson5910 can u plz explain me more i'm confused

10. jim_thompson5910

which part are you confused about?

11. jim_thompson5910

if you want, you can ask the question in a separate post

12. moha_10

all

13. jim_thompson5910

$\Large \frac{x^2 - 16}{x+4}$ $\Large \frac{x^2 - 4^2}{x+4}$ $\Large \frac{(x-4)(x+4)}{x+4}$ $\Large \frac{(x-4)\cancel{(x+4)}}{\cancel{x+4}}$ $\Large x-4$ So $\Large \frac{x^2 - 16}{x+4}$ simplifies to $\Large x-4$ Keep in mind that x cannot equal -4 in the original expression. So for the two expressions to be completely equivalent, x cannot equal -4 in the final expression.