Question

on a number line, suppose point E has a coordinate of 3, EG=6, and EX=12. is G the midpoint of EX? what are the possible coordinates for G and X?

Answer 1

• could be, isn't necessarily
• G = -3 or 9; X = -9 or 15

Explanation:

If E is 3 and EG is 6, then ...

G = E ± EG = 3 ± 6

G = -3 or 9

If E is 3 and EX is 12, then ...

X = E ± EX = 3 ± 12

X = -9, or 15

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If X and G have the same sign, then G will be the midpoint of EX. If not, then G is not the midpoint.

That is, -3 is halfway between -9 and 3, just as +9 is halfway between 3 and +15. On the other hand, -3 is not between 3 and 15; nor is 9 between 3 and -9.