giúp tui với :/\ !! nhanh nhé >:D

$\text{#nan}$


$\text{a) }$
 
$\text{A = $\frac{x² - 12x + 36}{2x² - 72 }$ }$

$\text{A = $\frac{(x - 6)²}{2(x² - 36}$ }$

$\text{A = $\frac{( x - 6 ) ( x - 6 )}{2( x - 6 ) x + 6 )}$ }$

$\text{A = $\frac{x - 6}{2(x+ 6 )}$ }$

_______________________________

$\text{b) }$

$\text{Với x = $\frac{-3}{2}$ }$

$\text{thì A = $\frac{x - 6}{2(x+6)}$ }$

$\text{= $\frac{-\frac{-3}{2}-6 }{2[-\frac{-3}{2}+6] }$ }$

$\text{= $\frac{-\frac{15}{2} }{2. \frac{9}{2}}$ }$

$\text{= $\frac{-5}{6}$ }$