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Match the pairs of equations that represent concentric circles

Match the pairs of equations that represent concentric circles-example-1
User AnIBMer
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1 Answer

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Answer:

The 3rd equation on the left column and second one on the right column.

Explanation:

These 2 equations have same coefficients of x and y if we divide the first one by 4 and the second by 2.

This gives the 2 equations

x^2 + y^2 - 4x + 6y - 7 = 0

x^2 + y^2 - 4x + 6y - 20 = 0

If we compete the square on these we get

(x - 2)^2 + (y + 3)^2 = 20

(x - 2(^2 + (y + 3)^2 = 33

These are in standard form . The center is the same (2, -3) but the radii are different so they are concentric.

User Arturo
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