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.
Answer:
g(-7)=5
Step-by-step explanation:
-2(-7)-9
14-9=5
Answer:
sjdifsjdhfifkfkfifjfjfofof
Applying the Trigonometry ratio, CAH, the missing side is, x = 1.9.
<h3>How to Solve a Right Triangle Using Trigonometry Ratio</h3>
The Trigonometry Ratios are:
- SOH - sin∅ = opp/hyp.
- CAH - cos∅ = adj/hyp.
- TOA - tan∅ = opp/adj.
Thus, given:
∅ = 51°
hyp = 3
adj = x
cos 51 = x/3
x = (cos 51)(3)
x = 1.9
Thus, applying the Trigonometry ratio, CAH, the missing side is, x = 1.9.
Learn more about Trigonometry Ratio on:
brainly.com/question/4326804
Answer:
n = -4
Step-by-step explanation:
Notice how in the previous examples they all divide by 2? It is the same case here. So now the question is... "what" divided by "2" is "-2".
Let me show you:
n ÷ 2 = -2
if you know your integer math, you should know that...
-4 ÷2 = -2 (this is the correct equation)
