Goi A(a;12-2a); B(b;b-2); C(5c-3;c)
=>→BC(5c−b−3;c−b+2) vuong goc vs →AH
=>5c−b−3=2(c−b+2)=>b=7−3c(1)
ta co trung diem M cua AB toa do la M(a+b2;10−2a+b2)∈CM
=>b=a114−11=7−3c
=>→BA(−b711+4;−b1911+6)+→BC(8b−263;4b−133)=k.→BD(1;−1)
=>−b711+4+8b−283=−(−b1911+6+4b−133)⇔b=−12154=>a;c=..........