SOLUTION: find all points having an x coordinate of 4 whose distance from the point (-2, -1) is 10

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Question 1053816: find all points having an x coordinate of 4 whose distance from the point (-2, -1) is 10
Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
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The same as saying, the distance from (4,y) to (-2,-1) is 10.
Use the distance formula.

sqrt%28%284-%28-2%29%29%5E2%2B%28y-%28-1%29%29%5E2%29=10
%284%2B2%29%5E2%2B%28y%2B1%29%5E2=100
36%2By%5E2%2B2y%2B1=100
y%5E2%2B2y=100-37
y%5E2%2B2y-63=0
-
y=%28-2%2B-+sqrt%28256%29%29%2F2

y=%28-2%2B-+16%29%2F2
y=7 or y=9

The points will be (4,7) and (4,9).