Question

Por favor me ajudem

Answer 1

(x/x²-16)+(3/x+4)

5/5²-16+3/5+4

5/9+3/9

8/9

:)

Answer 2

$\frac{1}{x-x^{2}} - \frac{9}{ x^{2} +3x} (Substituindo x=4)$

$\frac{1}{4-4^{2}} - \frac{9}{ 4^{2} +3.4}$

$\frac{1}{4-16} - \frac{9}{28}$ 

$\frac{1}{-12} - \frac{9}{28} (MMC entre 12 e 28 =84)$  

$\frac{-7-27}{84} = \frac{-34}{84} = \frac{-17}{42}$