Hi I encountered this DS problem and not sure if the answer is right...
On the number line shown, is zero halfway between r and s?
----r---- s---- t---
1). s is to the right of zero
2). the distance between t and r is the same as the distance between t and -s.
OA: C, but don't understand why its not b.
This is what I did.
|t-r| = |t - (-s)| = |t+s|;
possibility
if r,s,t all negative then -t+r = -t-s and r = -s
if t is positive while s,r negative then t+r = t-s and r = -s
if t,s both positive while r is neg then t+r = t+s and r = s but this can't be since s is to the right of r.
if t, s, r are all positive then t-r = t+s and -r = s
other words don't they all show that r and s are same value but different sign and thus 0 is the midpoint?
On the number line shown, is zero halfway between r and s?
----r---- s---- t---
1). s is to the right of zero
2). the distance between t and r is the same as the distance between t and -s.
OA: C, but don't understand why its not b.
This is what I did.
|t-r| = |t - (-s)| = |t+s|;
possibility
if r,s,t all negative then -t+r = -t-s and r = -s
if t is positive while s,r negative then t+r = t-s and r = -s
if t,s both positive while r is neg then t+r = t+s and r = s but this can't be since s is to the right of r.
if t, s, r are all positive then t-r = t+s and -r = s
other words don't they all show that r and s are same value but different sign and thus 0 is the midpoint?
