Question 1109088
Let the other endpoint be ( a, b )
I can say:
(1) {{{ ( -5 + b ) / 2 = -7 }}}
(2) {{{ ( -5 + a ) / 2 = -10 }}}
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(1) {{{ -5 + b = -14 }}}
(1) {{{ b = -9 }}}
and
(2) {{{ -5 + a = -20 }}}
(2) {{{ a = -15 }}}
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The othrr endpoint is at ( -15, -9 )