Please this question is for survey engineering, which has to solve by Least Square Adjustment (LSA) using matrices. Thanks in advance.

The following figure shows a level net that is observed with the following results: the elevation differences and standard deviations are given in metres, and the elevation of A is 437.596 m, From A B C To A B D B D Std. dev. (m) 0.006 0.004 0.005 AElev (m) lev (m) 10.509 -7.348 5.360 -3.167 -8.523 15.881 What are the most probable values for the elevations of B, C, and D? From C D B A To Std. dev. (m) 0.003 0.004 0.012 A D C