Question

Three of these expressions give the distance between point A and point B on the number line

Which expression does NOT
A. |7.4-3.5|
B. |7.5+3.5|
C. |- 3.5-7.5|
D. |7.5-(-3.5)|

Answer 1

Option A does not give the right expression.

Explanation:

On the number line if there are two points P(a) and Q(b) given by coordinates a and b, then the distance between those two points will be given by

d = |a - b| ......... (1)

which is independent of the position of the points.

Therefore, if point A is at - 3.5 and point B is at 7.5, then the distance between point A and point B will be given by |7.5+3.5| or |- 3.5-7.5| or |7.5-(-3.5)|, but not by |7.4-3.5|.

Hence, option A does not give the right expression. (Answer)