Point B has coordinates ​(2​,1​). The​ x-coordinate of point A is -10. The distance between point A and point B is 15 units. What are the possible coordinates of point​ A?

Respuesta :

Answer:

(-10, 10) or (-10, -10)

Step-by-step explanation:

[tex]d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2[/tex]

[tex]15 = \sqrt{(-10 - 1)^2 + (y_2 -2 )^2}[/tex]

[tex]15 = \sqrt{121 + 2y + y^2 + 4}[/tex]

[tex](15)^{2} =( \sqrt{121 + 2y + y^2 + 4})^{2}[/tex]

[tex]225 = 121 + 2y + y^2 + 4[/tex]

[tex]225 = 125 + 2y + y^2[/tex]

[tex]0 = -100 + 2y + y^2[/tex]

[tex]0 = (y + 10)(y - 10)[/tex]