Find k,if the following matrices are singular:`[[k-1,2,3],[3,1,2],[1,-2,4]]`

Find k,if the following matrices are singular: [[7,3],[-2,k]]

Find k,if the following matrices are singular: [[4,3,1],[7,k,1],[10,9,1]]

Which of the following marices are singular or non singular? [[3,5,7],[-2,1,4],[3,2,5]]

Verify that A(B+C)=AB+AC in each of the following matrices A=[[1,-1,3],[2,3,2]],B=[[1,0],[-2,3],[4,3]] and C=[[1,2],[-2,0],[4,-3]]