Find the value of a, b, c and d if: [ array*20c a - b&2a + c 2a - b&3c + d array ] = [ array*20c - 1&5 0&13 array ]
We can see that after simplifying, a = 1, b = 2, c = 3, d = 4 is left. The method is simple: formula → substitution → calculation → answer.
Ref: NCERT Mathematics Class XII — Matrices and Determinants
