Midpoint formula is M=( (x1+x²)/2 , (y1+y²)/2 )
let A be there point (x1,y1), our (2,3)
plug into the formula to get
(-2,1)=( (2+x²)/2, (3+y2)/2 )
so -2=(2+x2)/2 and 1=(3+y2)/2
x2=-6 and y2=-1
answer is B
<span>686.924 to the nearest ten is 690.0 because the ones place is a number of 5 and above, which means you must move the tens place up 1 value.</span>
Answer:

Step-by-step explanation:
Part (a) the probability that two people have a birthday on the 9th of any month.
Neglecting leap year, there are 365 days in a year.
There are 12 possible 9th in months that make a year calendar.
If two people have birthday on 9th; P(1st person) and P(2nd person).

Part (b) the probability that two people have a birthday on the same day of the same month
P(2 people selected have birthday on the same day of same month) + P(2 people selected not having birthday on same day of same month) = 1
P(2 people selected not having birthday on same day of same month):

P(2 people selected have birthday on the same day of same month) 
If two angles are equal, then the two angles are obtuse.