Can sometime tell me why the discriminate b^2-4ac doesn't identify trinomial 3x^2+4x-15 as something that's factorable with two answers? I keep getting a negative number using the discriminate.

Discriminant = 196

Step-by-step explanation:

y = 3x² + 4x - 15

   a=3    b=4   c=-15

Discriminant = b² - 4ac

                     =(4)² - 4(3)(-15)

                     = 16 - (-180)

                     = 16 + 180

                     = 196

If b² - 4ac > 0, then there are 2 real roots/solutions/x-intercepts

If b² - 4ac = 0, then there is 1 real root/solution/x-intercept

If b² - 4ac < 0, then there are 0 real roots/solutions/x-intercepts

                                                (2 imaginary roots/solutions)

Since 196 is positive, there are 2 real roots

a) one student is chosen from classroom a, then a student is chosen from classroom b.  

step-by-step explanation:

independent events are ones in which the probability of one event does not affect the probability of the second event.

one student is chosen from classroom a; this does not affect the chances of choosing a student from classroom b.   this makes these independent events.

when one card is chosen from a standard deck and then set aside before a second card is chosen, the probability of the second card being chosen changes.   this makes them dependent events.

when one student is chosen from classroom a and then a second student is chosen from classroom a, the probability of choosing the second student changes.   this makes them dependent events.

when a letter is chosen from the alphabet and then a second letter is chosen, the probability of choosing the second letter changes.   this makes them dependent events.