Question 1053816
-removed-
-maybe more later-


The same as saying, the distance from  (4,y) to (-2,-1)  is 10.
Use the distance formula.


{{{sqrt((4-(-2))^2+(y-(-1))^2)=10}}}
{{{(4+2)^2+(y+1)^2=100}}}
{{{36+y^2+2y+1=100}}}
{{{y^2+2y=100-37}}}
{{{y^2+2y-63=0}}}
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{{{y=(-2+- sqrt(256))/2}}}


{{{y=(-2+- 16)/2}}}

y=7 or y=9


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