Question 1045189
Let the coordinates of L be:
L( x[1], y[1] )
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{{{ ( -7 + x[1] ) / 2 = -4 }}}
{{{ -7 + x[1] = -8 }}}
{{{ x[1] = -1 }}}
and
{{{ ( -3 + y[1] ) / 2 = -6 }}}
{{{ -3 + y[1] = -12 }}}
{{{ y[1] = -9 }}}
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L( x[1], y[1] ) = L( -1, -9 )
is the other endpoint