I will explain you and pair two of the equations as an example to you. Then, you must pair the others.
1) Two circles are concentric if they have the same center and different radii.
2) The equation of a circle with center xc, yc, and radius r is:
(x - xc)^2 + (y - yc)^2 = r^2.
So, if you have that equation you can inmediately tell the coordinates of the center and the radius of the circle.
3) You can transform the equations given in your picture to the form (x -xc)^2 + (y -yc)^2 = r2 by completing squares.
Example:
Equation: 3x^2 + 3y^2 + 12x - 6y - 21 = 0
rearrange: 3x^2 + 12x + 3y^2 - 6y = 21
extract common factor 3: 3 (x^2 + 4x) + 3(y^2 -2y) = 3*7
=> (x^2 + 4x) + (y^2 - 2y) = 7
complete squares: (x + 2)^2 - 4 + (y - 1)^2 - 1 = 7
=> (x + 2)^2 + (y - 1)^2 = 12 => center = (-2,1), r = √12.
equation: 4x^2 + 4y^2 + 16x - 8y - 308 = 0
rearrange: 4x^2 + 16x + 4y^2 - 8y = 308
common factor 4: 4 (x^2 + 4x) + 4(y^2 -8y) = 4*77
=> (x^2 + 4x) + (y^2 - 2y) = 77
complete squares: (x + 2)^2 - 4 + (y - 1)^2 - 1 = 77
=> (x + 2)^2 + (y - 1)^2 = 82 => center = (-2,1), r = √82
Therefore, you conclude that these two circumferences have the same center and differet r, so they are concentric.
0.035x+0.045x=427.50
0.08x=427.50
x=427.50/0.08
x=5343.75
x+x+1500=5343.75
2x=5343.75-1500
2x=3843.75
x=1921.88 first
1921.88+1500=3421.88 second
Answer:
F = 48
Step-by-step explanation:
F= 8/5 (c) + 40
Let c=5
F = 8/5 * 5 +40
= 8 + 40
= 48
Answer:
Spongebob Square Pants!
Step-by-step explanation:
Answer:
Option (1). 34°
Step-by-step explanation:
From the figure attached, CE and CD are the radii of the circle C.
Central angle CED formed by the intercepted arc DE = 68°
Since measure of an arc = central angle formed by the intercepted arc
Therefore, m∠CED = 68°
Since m∠EFD = 
[Central angle of an intercepted arc measure the double of the inscribed angle by the same arc]
Therefore, m∠EFD = 
= 34°
Therefore, Option (1) 34° will be the answer.
