clear,clc
B=[7 5.84 4.9016 4.1381;
    5.84 4.9016 4.1381 3.5131;
    4.9016 4.1381 3.5131 2.9986;
    4.1381 3.5131 2.9986 2.6420]
C=[20.05;
   16.642;
   13.8968;
   11.6731]

A=inv(B)*C