( 717, #55) Find an equation of the plane with x-intercept a,

( 717, #55) Find an equation of the plane with x-intercept a, y-intercept b, and z-intercept c.
Solution: Three points in the plane are ( a, 0, 0 ), ( 0, b, 0 ) and ( 0, 0, c ).
Let a be the vector from ( a, 0, 0 ) to ( 0, b, 0 ) :
a = < 0 - a, b - 0, 0 - 0 > = < -a, b, 0 >
Let b be the vector from ( a, 0, 0 ) to ( 0, 0, c ) :
b = < 0 - a, 0 - 0, c - 0 > = < -a, 0, c >
The normal of the two vectors is:

The general equation for a plane is:

by: nl