Which coefficient matrix represents a system of linear equations that has a unique solution?

What is the simplified form of 7 √x • 7 √x • 7 √x • 7 √x?

Express the following as a function of a single angle, cos(60) cos(-20) - sin(60) sin(-20)

An eight-sided die, which may or may not be a fair die, has four colors on it; you have been tossing the die for an hour and have recorded the color rolled for each toss. what is the probability you will roll a brown on your next toss of the die? express your answer as a simplified fraction or a decimal rounded to four decimal places.