Show that 0 and 1 are the only squares in z4 (a square is an element that is of the form a 2 for some a in z4). this proves that the square a 2 of an integer a is congruent to 0 or 1 modulo 4.

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?

You paid 28.00 for 8 gallons of gasoline. how much would you pay for 15 gallons of gasoline?

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?