">  -4.0000e+00   5.0000e+00  -7.0000e+00  -1.0000e+01
            0   1.6250e+01   2.5000e-01  -7.0000e+00
            0            0   5.5385e+00  -9.0769e+00
            0            0            0  -1.6667e-01
</div></div></div></div></div></div></div><div class = "S0"></div><div class = 'SectionBlock containment'><div class = "S1"><span class = "S2"><span class="S0">MATLAB has engineered the backslash so that systems with triangular</span></span><span class = "S2"><span class="S0"> </span></span><span 