Use Gaussian elimination to find the complete solution to the system
of equations, or show that none exists.
5x + 18y - 20z = 13
2x + 9y - 11z = 1
x + 3y - 3z = 4
Select the correct choice below and, if necessary, fill in the answer
boxes to complete your choice.
A. There is one solution. The solution set is {($\boxed{}$,$\boxed{}$,$\boxed{}$)}.
(Simplify your answers.)
B. There are infinitely many solutions. The solution set is
{($\boxed{}$,$\boxed{}$, z)}, where z is any real number.
(Type expressions using z as the variable. Use integers or
fractions for any numbers in the expressions.)
C. There is no solution. The solution set is Ø.