Question

Answer 1

Gọi `C(x;x+2) in \Delta`

Vì `\triangle ABC` vuông tại `A=>AB \bot AC`

 `=>\vec{AB}.\vec{AC}=0`

`<=>(3;-1).(x-2;x+2-2)=0`

`<=>(3;-1).(x-2;x)=0`

`<=>3(x-2)-x=0`

`<=>3x-6-x=0`

`<=>x=3`

  `=>C(3;5)`

   `->bb C`