(A+B)+C = A+(B+C). This law of matrices is known as April 26, 2021 – by admin Question: (A+B)+C = A+(B+C). This law of matrices is known as A. cumulative law B. associative law C. distributive law D. identity law Answer» b. associative law Note: The above multiple-choice question is for all general and Competitive Exams in India.