Answer:
we have (a,b,c)=(4,-2,0) and R=4 (radius)
Step-by-step explanation:
since
x²+y²+z²−8x+4y=−4
we have to complete the squares to finish with a equation of the form
(x-a)²+(y-b)²+(z-c)²=R²
that is the equation of a sphere of radius R and centre in (a,b,c)
thus
x²+y²+z²−8x+4y=−4
x²+y²+z²−8x+4y +4 = 0
x²+y²+z²−8x+4y +4 +16-16 =0
(x²−8x + 16) + (y² + 4y + 4 ) + (z²) -16 = 0
(x-4)² + (y+2)² + z² = 16
(x-4)² + (y-(-2))² + (z-0)² = 4²
thus we have a=4 , b= -2 , c= 0 and R=4
The equation for area of a triangle is A= 1/2bh so a=1/2(12cm)(9.6cm)
-8, -19, -30, -49 , -60
<u>Step-by-step explanation:</u>
Here we have the following sequence :
-8, -19, -30, _ , _
- First term of sequence is -8 .
- Second term of sequence is -19 :
- Third term of sequence is -30 :
- Fourth term of sequence is :
- Fifth term of sequence is :
Following sequence was an AP( Arithmetic Progression ) with first term as -8 i.e. 
and common difference 
having general equation as : 
.
The answer is 21. 75²=5625 72²=5184 5625-5184=441 √441=21 so 21 is your answer. I hope this helps. The formula to figure out the hypotenuse A²+B²=C² can also be used to find a leg. Since we have one leg and the hypotenuse I was able to figure this out.
If you were to write it fully, as an equation, I believe it would look like this:
x²(4x-x) *4x
Therefore allowing you to simplify the area within the bracket into:
x²(3x)*4x
To expand, you simply start on the left and work your way across.
3x³*4x= 12x⁴
