100: \( (-5):(+4) * 8= \)

Let's break it down! First, we have to deal with the division: \( -5 \div 4 = -1.25 \). Next, we multiply that by 8: \( -1.25 * 8 = -10 \). So the final answer is \(-10\). Easy peasy, right? Now, if you ever find yourself scratching your head over signs in mathematics, just remember: multiplying or dividing two negative numbers gives you a positive result, while a negative and a positive always yield a negative. Keep that in your back pocket for future reference!