Science talk:Math Exam Resources/Courses/MATH221/April 2013/Question 02 (d)

The same code that verifies this solution is the following:

A = Matrix(QQ, 4,4,[[1,2,1,3],[3,4,9,0],[2,3,5,1],[2,2,8,-3]])

b = vector(QQ,[2,7,8,5])

print A\b // This returns (-39, 31, 0, -7)