Question

On a number line, point A has a coordinate of −6, and point B has a coordinate of 2. Which is the coordinate of point M, the midpoint of AB?
A:4

B:−2

C:0

D:−3

Answer 1

Answer:

The correct option is B.

Step-by-step explanation:

It is given that on a number line, point A has a coordinate of −6, and point B has a coordinate of 2. It means

$x_1=-6$

$x_2=2$

Midpoint formula:

$x=\frac{x_1+x_2}{2}$

$x=\frac{-6+2}{2}$

$x=\frac{-4}{2}$

$x=-2$

The coordinate of point M is -2. Therefore option B is correct.

Answer 2

To solve this, we just need to find the distance between the points A and B in the number line, and then, divide that distance by 2.
Remember that the distance formula between tow point in the number line is: 
$d=|x_{2}-x_{1}|$
From our point we can infer that $x_{1}=-6$ and $x_{2}=2$, so lets replace the values:
$d=|x_{2}-x_{1}|$
$d=|2-(-6)|$
$d=|2+6|$
$d=8$

Now, to find the coordinate of the midpoint, we just need to divide that distance by 2:
$M= \frac{8}{2}$
$M=4$

We can conclude that the coordinate of the point M, the midpoint of AB, is 4