A scientist is studying the temperature in a certain region of a remote planet. She approximates the temperature $T(x)($in degrees Celsius$)$ in that region $x$ years after the planet's origin to be the following.

$T(x)=\frac{-x-15}{16x^2-48x40}$

Complete the following.

$($a$)$ Use the ALEKS graphing calculator to find the value of $x$ that minimizes the temperature. Then give the minimum temperature. Round your answers to the nearest hundredth.

Value of $x$ that minimizes temperature: $$ years

Minimum temperature: $C$

$($b$)$ Complete the following sentence.

For very large $x,$ the temperature appears to

$$ undefined approach a finite value. decrease without bound. increase without bound.