Answer:
Option D.
3 equations with 3 variables
Step-by-step explanation:
The coordinates of a point in space must necessarily have 3 components. One to describe the distance on the x axis, another to describe the distance on the y axis to the point, and a third to describe the distance on the z axis.
If we have three variables, then 3 equations are needed to solve the system. With less than 3 equations it would be impossible to solver the system.
Therefore the correct answer is option D.
3 equations with 3 variables
Answer:
(1/2,-5/2)
Step-by-step explanation:

Hello I think the answer would be three.
No, it is impossible. Intuitively, a negative number sits at the left of 0 on the number line, and a positive number sits at the right of 0 on the number line. And a number x is greater than another number y if x sits at the right of y on the number line. So, every positive number is greater than any negative number.
Also, by definition, a positive number is greater than 0, and a negative number is smaller than zero. So, if x is positive and y is negative, you have

and since the relation of order "<" is transitive, this implies

The formula used to find the length of a line segment is the same formula as the Pythagoras theorem.
We take CD as the hypotenuse of the right-angled triangle and the distance between the x-coordinates and y-coordinates as the length of two short sides.
We can write the formula as
CD =

CD =