Question

urgente, rápido agrrrr

Answer 1

$1)~f(x)=x^2-3x~~~~~~~~~~~~~~f( \frac{-1}{4} )?$

$f( \frac{-1}{4} )=(\frac{-1}{4} )^2-3.( \frac{-1}{4} )$

$f( \frac{-1}{4} ) = \frac{1}{16}- \frac{(-3)}{4}$    

$f( \frac{-1}{4} )=\frac{1}{16} + \frac{3}{4}$           $c = 16$
 
$f( \frac{-1}{4} ) = \frac{1+12}{16} = \frac{13}{16}$
 
     $\boxed{resposta ~~letra~~c)}$


$2) -8=2-b+8$
$-8=10-b$
$b=+18$
$\boxed {alterativa ~~a)}$