Tom K. answered 11/14/20
Knowledgeable and Friendly Math and Statistics Tutor
[2, -4, 1] - [3, -2, 5] = [-1, -2, -4]
i j k
-1 -2 -4
5 1 -3
has determinant 10i - 23j + 9k
Then, consider the plane [2, -4, 1] + s[10, -23, 9] + t[5, 1, -3]
Alternatively, we can write the plane via
i j k
10 -23 9
5 1 -3
The determinant is 60i + 75j + 125k, which we may write as 5(12i + 15j + 25k)
Thus, an alternative equation for the plane is
12x + 15y + 25z = 12*2 + 15*-4 + 25 * 1 = -11
12x + 15y + 25z = -11