Question -
Answer -
Taking out commonfactors a, b, and c from R1, R2, and R3 respectively,we have:

Applying R2 → R2 − R1 andR3 → R3 − R1, we have:

Applying C1 → aC1, C2 → bC2, andC3 → cC3, we have:

Expanding along R3, we have:

Hence, the given resultis proved.