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26 votes
26 votes
The points (-3, 12) and (-1, r) lie on a line with slope - 3. Find the missing coordinate r.

User Kelvin Barsana
by
2.6k points

1 Answer

16 votes
16 votes

Answer:

r = 6

Explanation:

(12-r) / ((-3-(-1)) = -3/1


(12-r)/(-2) = -3

cross-multiply:

12 - r = 6

subtract 12 from each side:

-r = -6

divide each side by -1:

r = 6

User Daralyn
by
3.0k points