Exercise 39 Page 172

The given system consists of equations of planes. We will use the Substitution Method to solve this system. When using this method, it is necessary to isolate a variable. In the third equation, it will be easiest to isolate z. With a variable isolated in one of the equations, we can substitute its equivalent expression into the remaining equations. In the final step of the simplification of these substitutions, our goal is to have yet another variable isolated. This time, the y-variable was isolated in the first equation. We can now substitute its equivalent expression into the second equation. The value of x is 2. Substituting 2 for x into the first and the third equations, we can find the values of y and z. The solution to the system is the point (2,4,6). This is the singular point at which all three planes intersect.