Question 989604
The distance formula is,
{{{D=sqrt((x[2]-x[1])^2+(y[2]-y[1])^2)}}}
Squaring both sides and substituting with known information,
{{{100=(4-(-2))^2+(y-(-1))^2}}}
{{{100=(4+2)^2+(y+2)^2}}}
{{{100=6^2+(y+2)^2}}}
{{{(y+2)^2=64}}}
{{{y+2=0 +- 8}}}
{{{y=-2 +- 8}}}
{{{y=-10}}} and {{{y=6}}}
({{{4}}},{{{-10}}}) and ({{{4}}},{{{6}}})