Answer:
I would love to help, Could you put the question in English?
Explanation:
Answer:
Options B, A, D, C
Explanation:
When a scientists, let's say Roberto wonders if the presence of other elements also affects the color of a flame, he can decide to prove this through a study. Therefore, in chemistry class, Roberto sees that traces of lithium makes a flame appear bright red. Subsequently, Roberto designs an experiment to test flame color in the presence of different elements and finally Roberto's friend tells him the color of a flame cannot be changed, but Roberto is still unsure.
The practice of playing top hits several times a day on radio stations is called rotation.
The equation of our ellipse is:
(1)
First, let's reduce the equation of the ellipse to the standard form:
To do that, we should divide both terms of equation (1) by 6400, and we get:
This is a vertical ellipse (because 
) centered in the origin, and so the distance of its foci from the origin (on the y axis) is given by
Therefore, the position of the two foci is (0,6) and (0,-6)
