1. The problem statement, all variables and given/known data |A| + |B| = |C| where A= [a_11 a_12 a_13] [a_21 a_22 a_23] [a_31 a_32 a_33] B= [b_11 b_12 b_13] [b_21 b_22 b_23] [b_31 b_32 b_33] C= [(a_11 + b_11) a_12 a_13] [(a_21 + b_21) a_22 a_23] [(a_31 + b_31) a_32 a_33] 2. Relevant equations ? 3. The attempt at a solution First I tried taking the determinants of all 3 matrices but it got like WAY too messy and I didnt see anything close to them being equal (since i got a lot of terms that involved a_ij x b_ij and I didnt get them on the other ones. Then I researched a little and came across that A= [a_11 a_12 a_13] = [a_11 a_12 a_13] + [ 0 a_12 a_13] + [0 a_12 a_13] [a_21 a_22 a_23] [0 a_22 a_23] [a_21 a_22 a_23] [0 a_22 a_23] [a_31 a_32 a_33] [0 a_32 a_33] [0 a_32 a_33] [a_31 a_32 a_33] I think it goes somewhere around there but I keep getting lost and I dont know how to get around it.