Answer:
(a)
,
,
,
,
,
,
.
(b)
,
,
,
,
,
,
,
.
Step-by-step explanation:
In this exercise we only need to recall the formula for C(n,k):

where the symbol
is the factorial and means
.
By convention 0!=1. The most important property of the factorial is
, for example 3!=1*2*3=6.
(a) The explanations to the solutions is just the calculations.
.
(b) The explanations to the solutions is just the calculations.
For all the calculations just recall that 4! =24 and 5!=120.
Answer:
15$
Step-by-step explanation:
The expression x^2 -7x + 10 can be written in factored form as given by Option C: (x-2)(x-5)
<h3>How to find the factors of a quadratic expression?</h3>
If the given quadratic expression is of the form 
then its factored form is obtained by two numbers alpha( α ) and beta( β) such that:

Then writing b in terms of alpha and beta would help us getting common factors out.
Sometimes, it is not possible to find factors easily, so using the quadratic equation formula can help out without any trial and error.
For this case, we're provided the expression:

We can write 10 as multiple of -5 and -2 and
we can write -7 as sum of -5 and -2. Thus, we get:

Thus, the expression x^2 -7x + 10 can be written in factored form as given by Option C: (x-2)(x-5)
Learn more about factorization of quadratic expression here:
brainly.com/question/26675692