Write the equation of the graph below.

-x²+8x-15

Step-by-step explanation:

There are two solutions: 3 and 5

First, let's write the equation in this form (pay attention, the parabola here is going up so it won't be like your graph):

(x-3)(x-5)

For resolve our problem, let's re-write it with a minus before:

-(x-3)(x-5)

You can also expand it and the result will be like this:

-x²+8x-15

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.

it would be 6xy and -16xy.