Answer:
a and c
Step-by-step explanation:
i am for sure
The radius of the given circle is 5 units with the equation x²+y²+8x-6y+21=0.
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What are circles?</h3>
All points in a plane that are at a certain distance from the center combine to form a circle.
It is the curve that a moving point in a plane draws to keep its distance from another point constant, to put it another way.
In the center of a circle, equal chords subtend equal angles.
So, the radius of the circle with equation x² + y² + 8x – 6y + 21 = 0:
General form:
(x – a)² + (y-b) = r²
x² + y² – 2ax – 2by + (a² + b² – r²) = 0
We know that: r = √(a² +b²)
Compare the following equation to the equation's general form.
We obtain:
-2ax = 8x ⇒ a = – 4
-2by = -6y ⇒ b = 3
r = √((-4)2 +32 ) = √16 + 9 = √25 = 5
Therefore, the radius of the given circle is 5 units with the equation x²+y²+8x–6y+21=0.
Know more about circles here:
brainly.com/question/24375372
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Correct question:
What is the radius of a circle whose equation is x² + y² + 8x – 6y + 21 = 0?
By Pythagoras’ theorem,
BD square= AB square + BC square
BD square= 3.15 square + 1.77 square
BD Square=13.0554
BD= square root 13.0554
BD=3.61 (to 3sf)
Answer:
m + n = 26 and n = 2m + 5
m = 7, n = 19
Step-by-step explanation:
Because we know that the sum of m and n is 26, we get the first equation. For the second equation, we are told that n is five more than twice m. So we multiple m by 2 and then add 5 to that to get what n is. This is our second equation.
We plug the second equation in for n in the first equation to get
m + (2m + 5) = 26
3m + 5 = 26
3m = 21
m = 7
And then for n, we solve the first equation to get
7 + n = 26
n = 19