Answer:
The possible coordinates of the midpoint are -10.5 and 10.5
Step-by-step explanation:
The given parameters are;
The coordinate of A = 0
The distance from A to R which is the same as AR = 21
Given that R is on the number line, we have;
When R is on the left side of A, which is = 0 - 21 = -21, we have;
The coordinates of the midpoint, M from -21 to 0 is given as follows;
M = (A + R)/2 = (0 - 21)/2 = -10.5
When R is on the right side of A, which is = 21 - 0 = 21, we have;
The coordinates of the midpoint, M from 21 to 0 is given as follows;
M = (A + R)/2 = (0 + 21)/2 = 10.5
Therefore, the possible coordinates of the midpoint are -10.5 and 10.5.