Question

Dada a função f(x) = -x^2 + 5x + 6, calcule:
f(-4/5) = ?

Answer 1

-(-4/5)^2+5*4/5+6
-16/25-4+6
-16/25-2
34/25
sendo assim f(-4/5)=34/25

Answer 2

$f(x)=-x^2+5x+6$
$f(-\frac{4}{5})=-(-\frac{4}{5})^2+5*(-\frac{4}{5})+6$
$f(-\frac{4}{5})=-\frac{16}{25}-4+6$
$f(-\frac{4}{5})=-\frac{16}{25}+2$
$f(-\frac{4}{5})=-\frac{16}{25}+\frac{2*25}{25}$
$f(-\frac{4}{5})=\frac{-16+50}{25}$
$\boxed{f(-\frac{4}{5})=\frac{34}{25}}$