ont-style: normal; color: rgb(64, 64, 64); font-size: 12px;">b = </span></div><div style="white-space: pre; font-style: normal; color: rgb(64, 64, 64); font-size: 12px;">     4
     9
    29
    40
</div></div></div></div></div></div></div><div class = "S0"></div><div class = 'SectionBlock containment'><div class = "S1"><span class = "S2"><span class="S0">It has a perfectly good solution, obtainable through LU factorization.</span></span></div><div class = 'CodeBlock contiguous'><div class = 'inlineWrapper'