957375…: “Underneath the humid parallelogram”

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Find the equation of the plane that passes through the points $(1,2,0)$ , $(-1,1,1)$ , and $(2,0,0)$ . Express your final answer in the form $ax+by+cz=d$ , where $a$ is positive, and $a$ , $b$ , $c$ , and $d$ have no common factors. $\answer {2}x+\answer {1}y+\answer {5}z=\answer {4}$

Use the three points to find two vectors that are parallel to the plane. How can you find a vector that is orthogonal to both of these vectors?