%Cas 1 A1 = [5.09056, 0.34992, -1.57784, -1.02756, -1.88282; 0.34992, 7.31489, -0.58246, -2.17175, -0.99596; -1.57784, -0.58246, 4.36274, 1.20557, -2.37391; -1.02756, -2.17175, 1.20557, 3.29363, -0.60668; -1.88282, -0.99596, -2.37391, -0.60668, 5.93819]; b1=[1:5]'; x1=mldivide(A1,b1) %Cas 2 A2=A1(1:4,:); b2=[1:4]'; x2=mldivide(A2,b2) %Cas 3 A3=A1(:,1:4); b3=[1:5]'; x3=mldivide(A3,b3)Donner des instructions équivalentes à mldivide dans chacun des cas.