Answer:
Step-by-step explanation:
You have to use the discriminant for this. If the quadratic is 
, then
a = -4, b = -3, and c = 7. The formula for finding the discriminant is
which comes from the quadratic formula, but without the square root sign. Filling in:
which simplifies down to
D = 9 + 112 so
D = 121. This is a perfect square, so the solutions will be 2 real. Just so you know, you will NEVER have a solution like the one offered in the third choice down. If you have one imaginary root, you will ALWAYS have a second by the conjugate rule.
(a-b)^2 = a^2-2ab+b^2
(8-5i)^2 = 8^2-2(8)(5i)+(5i)^2
= 64-80i+25i^2
i^2=-1
So
= 64-80i+25(-1)
=64-25-80i
= <em><u>39 - 80i</u></em>
which is your answer :)
Answer:
5/6 probability
Step-by-step explanation:
Answer:
The maximum number of songs that the symphonic choir can record is 14
Step-by-step explanation:
Let
x ----> the number of songs of the symphonic choir
we know that
The number of songs of the jazz choir multiplied by its average time per song plus the the number of songs of the symphonic choir multiplied by its average time per song, must be less than or equal to 72 minutes
so
The inequality that represent this situation is
solve for x
subtract 21 both sides
divide by 3.6 both sides
therefore
The maximum number of songs that the symphonic choir can record is 14
the answer is:
42.5
......
i commented the explanation in my answer
