Answer:

Step-by-step explanation:
we know that
<u><em>Combinations</em></u> are a way to calculate the total outcomes of an event where order of the outcomes does not matter.
To calculate combinations, we will use the formula

where
n represents the total number of items
r represents the number of items being chosen at a time.
In this problem

substitute

simplify



I think it’s 30 not gonna lie I’m gonna get somebody
Let’s see if there’s anyone!!!!!!!!!!!!
A.
Step-by-step explanation:
(180-x)-40=X
140 -x=X
140= 2x
x=140/2
x=70
the answer is 70 degree
If it has rational coefients and is a polygon
if a+bi is a root then a-bi is also a root
the roots are -4 and 2+i
so then 2-i must also be a root
if the rots of a poly are r1 and r2 then the factors are
f(x)=(x-r1)(x-r2)
roots are -4 and 2+i and 2-i
f(x)=(x-(-4))(x-(2+i))(x-(2-i))
f(x)=(x+4)(x-2-i)(x-2+i)
expand
f(x)=x³-11x+20