Answer:
C. 1 / (a(a - 1))
Step-by-step explanation:
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Just know that:
n! = n(n-1)!
= n(n-1)(n-2)!
= n(n-1)(n-2)(n-3)!
= ...
Answer:
The value of c that completes the square
is 1
Step-by-step explanation:
We need to find the value of c that completes the square 
The formula used will be: 
In the question given the value c can be found by breaking the middle term. we are given 2x while the general formula is 2ab for middle term so,
2(x)(1) = 2x
so, c= 1
Solving:

So, the value of c that completes the square
is 1
A number considered in relative relation to a whole number.
Answer:
x=7
Step-by-step explanation:
Add 10 to both sides to isolate x.
4x=28
x=7