Answer:
The value of k is 5.
Step-by-step explanation:
Since we know we can convert function's quadratic form to vertex form by completing the square.
f(x)=x2?6x+14
We will add and subtract 9 to our equation in order to complete the square.

Upon completing the square and combining like terms we will get,

Upon comparing Willie's vertex form with our expression we can see that k is 5.
Therefore, the value of k is 5.
All you have to do is multiply it then you get the answer
Given:
Violinists : Cellists = 7:3.
Number of violinists in the school orchestra = 21
To find:
The combined number of cellists and violinists.
Solution:
Let the number of violinists and cellists in the school orchestra are 7x and 3x respectively.
Then, combined number of cellists and violinists is

...(i)
Number of violinists in the school orchestra = 21

Divide both sides by 7.

Now, the combined number of cellists and violinists is
[Using (i)]

Therefore, the combined number of cellists and violinists is 30.
13 + 3i
15 - 6i - 2 + 9i → Sum
collect like terms
(15 - 2) + ( - 6i + 9i) =13 + 3i