The format for the equation of a circle is (x-h)^2+(y-k)^2=r^2, where (h,k) is your center and r is your radius. All we have to do is substitute the correct values, giving us the equation (x+2)^2+(y-1)^2=4
:)
Answer: D. 
Step-by-step explanation:
Using exponent rules an exponent to the power of a number will multiply by each other.
So the -4 and -9 will multiply.
The 6 in the numerator will now have a positive exponent of 36.

Now we can divide and when we do so the exponents will subtract from each other.
So 36 - 6 = 30
And the base of 6 does not change.
The simplified form is 
Answer:
62.4 square centimeters
Step-by-step explanation:
The picture of the question in the attached figure
we know that
The surface area of the triangular pyramid is equal to the area of the triangular base plus the area of its three lateral triangular faces
In this problem the triangles are equilateral, that means, the
surface area is equal to the area of four congruent equilateral triangles
so
![A=4[\frac{1}{2}(b)(h)]](https://tex.z-dn.net/?f=A%3D4%5B%5Cfrac%7B1%7D%7B2%7D%28b%29%28h%29%5D)
we have

substitute
![A=4[\frac{1}{2}(6)(5.2)]=62.4\ cm^2](https://tex.z-dn.net/?f=A%3D4%5B%5Cfrac%7B1%7D%7B2%7D%286%29%285.2%29%5D%3D62.4%5C%20cm%5E2)