Subtract the sum of
(8a-6a²+9) and (-10a-8+8a²) from 3

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-2a² + 2a + 2

Step-by-step explanation:

Given worded expression

subtract the sum of  (8a-6a²+9) and (-10a-8+8a²) from 3

Convert to numerical expression

3 - [(8a - 6a² + 9) + (-10a - 8 + 8a²)]

Expand parentheses in the bracket

=3 - [8a - 6a² + 9 - 10a - 8 + 8a²]

Combine like terms in the bracket

=3 - [(-6a² + 8a²) + (8a - 10a) + (9 - 8)]

=3 - [2a² - 2a + 1]

Expand bracket

=3 - 2a² + 2a - 1

Combine like terms

=-2a² + 2a + (3 - 1)

=

Hope this helps!! :)

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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.