If the points (p,q) (m,n)and (p-m)(q-n)are collinear ,then prove that

1.	If the points (p,q) (m,n)and (p-m)(q-n)are collinear ,then prove that pn-qm
Answer» Given points are collinear. Therefore[p {tex}\\times{/tex}\xa0n + m(q - n) + (p - m) q] - [m {tex}\\times{/tex}\xa0q + (p - m) n + p (q - n)] = 0{tex}\\Rightarrow{/tex}\xa0(pn + qm - mn + pq - mq) - (mq + pn - mn + pq - pn) = 0{tex}\\Rightarrow{/tex}\xa0(pn + p q - mn) - (mq - mn + pq) = 0{tex}\\Rightarrow{/tex}\xa0pn - mq = 0{tex}\\Rightarrow{/tex}\xa0pn = qm

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