Question 404086
{{{(1-0)^2 + (1-b)^2 = (2-0)^2 + (-1-b)^2}}}
==> {{{1 + 1-2b + b^2 = 4 + 1 + 2b + b^2}}}
<==> {{{2 - 2b + b^2 = 5 + 2b + b^2}}}
<==> {{{-3 = 4b}}} ==> {{{b = -3/4}}}.