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Y = 3x - 4

2x + y = 1

When graphed in the xy-plane, the lines described by the equations above each include a diameter of a circle. If the circle includes the point (-2, -5), which of the following is the equation of the circle?

HELP AND EXPLAIN. THANK YOU!!

Y = 3x - 4 2x + y = 1 When graphed in the xy-plane, the lines described by the equations-example-1
User CBIII
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5.4k points

2 Answers

7 votes

Final answer:

The equation of the circle is (x - 1)^2 + (y + 1)^2 = 25, with its center at the intersection of the given lines (1, -1) and a radius of 5 determined by the distance from the center to the point (-2, -5).

Step-by-step explanation:

To find the equation of the circle described by the equations y = 3x - 4 and 2x + y = 1 that has diameters along these lines, we first need to find their intersection which will be the center of the circle. Solving the system of equations for x and y gives us the center of the circle.

  1. Replace y in the second equation with the expression from the first equation, 3x - 4:

    2x + (3x - 4) = 1.
  2. Simplify and solve for x:

    5x - 4 = 1
    5x = 5
    x = 1.
  3. Substitute x = 1 into the first equation to find y:

    y = 3(1) - 4
    y = -1.
  4. The center of the circle is (1, -1).
  5. Now calculate the radius using the distance formula with the center (1, -1) and the given point (-2, -5) on the circle:

    r = √[(-2 - 1)² + (-5 - (-1))²]
    r = √(9 + 16)
    r = √25
    r = 5.
  6. Finally, write the equation of the circle using the center-radius form:

    (x - 1)² + (y + 1)² = 5².

The equation of the circle is (x - 1)² + (y + 1)² = 25.

User Joe The Person
by
5.6k points
3 votes

Answer:

the correct answer would be (B)

Step-by-step explanation:

Y = 3x - 4 2x + y = 1 When graphed in the xy-plane, the lines described by the equations-example-1
Y = 3x - 4 2x + y = 1 When graphed in the xy-plane, the lines described by the equations-example-2
User Martin Calvert
by
5.6k points