The following linear systems Ax = b have x as the actual solution and  as an approximate solution. Using the results of Exercise 2, compute


a. 0.03x1 + 58.9x2 = 59.2,
5.31x1 − 6.10x2 = 47.0,
x = (10, 1)t ,
 = (30.0, 0.990)t .
b. 58.9x1 + 0.03x2 = 59.2,
−6.10x1 + 5.31x2 = 47.0,
x = (1, 10)t ,
 = (1.02, 9.98)t .
c. x1 − x2 − x3 = 2π,
x2 − x3 = 0,
− x3 = π.
x = (0,−π,−π)t ,
 = (−0.1,−3.15,−3.14)t .
d. 0.04x1 + 0.01x2 − 0.01x3 = 0.06,
0.2x1 + 0.5x2 − 0.2x3 = 0.3,
x1 + 2x2 + 4x3 = 11,
x = (1.827586, 0.6551724, 1.965517)t ,
 = (1.8, 0.64, 1.9)t .