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A circle is centered at the point (-7, -1) and passes through the point (8, 7). The radius of the circle is ______ units. The point (-15, __) lies on this circle.

a) 13; -9
b) 10; -16
c) 12; -8
d) 15; -2

1 Answer

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Final answer:

The radius of the circle with a center at (-7, -1) and passing through (8, 7) is calculated as 17 units using the distance formula. However, this does not match any of the options provided in the question, suggesting an issue with the question or choices. As a result, the y-coordinate of the point (-15, __) that lies on this circle cannot be determined from the options given.

Step-by-step explanation:

The question is asking for the radius of the circle and the missing coordinate for the point that lies on the circle. To find the radius, we must use the distance formula, which is √((x_2 - x_1)^2 + (y_2 - y_1)^2), where (x_1, y_1) and (x_2, y_2) represent the coordinates of two points. Here, the center of the circle is (-7, -1) and it passes through the point (8, 7).

To calculate the radius: √((8 - (-7))^2 + (7 - (-1))^2) = √((8 + 7)^2 + (7 + 1)^2) = √(15^2 + 8^2) = √(225 + 64) = √289 = 17 units. Therefore, the radius is 17 units, which is not listed in the provided options, indicating a possible error in the question or options. Since this result is not among the options, we cannot accurately solve for the y-coordinate of the point (-15, __) on the circle.

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