Answer:
X=4
Step-by-step explanation:
5x-4=16
+4 +4 Add 4 on both sides
5x=20 Divide both sides by 5
x= 4
Hope this helps!
The radius of the given circle is 5 units with the equation x²+y²+8x-6y+21=0.
<h3>
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?
Answer:56.52
Step-by-step explanation:2x3.14=6.28
6.28x3=18.84
18.84x3=56.52
The answer is D 1 and 17/60