Question 835893
(0,b) to (4,4) is
{{{ d[1] = sqrt( (4 - 0 )^2 + ( 4 - b )^2 ) }}}
(0,b) to (5,-4) is
{{{ d[2] = sqrt( ( 5 - 0 )^2 + ( -4 - b )^2) }}}
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{{{ sqrt( (4 - 0 )^2 + ( 4 - b )^2 ) = sqrt( ( 5 - 0 )^2 + ( -4 - b )^2) }}}
Square both sides
{{{ 4^2 + ( 4-b )^2 = 5^2 + ( -4 -b )^2 }}}
{{{ 16 + ( 4-b )^2 = 25 + ( -4-b )^2 }}}
{{{ (4-b)^2 - ( -4-b )^2 = 25 - 16 }}}
Solve for {{{b}}} -you can finish