Algebra determinant

Question

(a) Consider the matrix

A = first row: 1 2 1 2 -1

second row: 3 1 -2 -3 1

third row: -1 2 4 4 6

fourth row: 0 0 0 1 2

fifth row: 0 0 0 -4 -5

Calculate the determinant of A, showing working.

(b) Given that

|G| = first row: a b c

second row: d e f

third row: g h i

= 17

then determine the value of

first row: 2a 2b 2c

second row: g h i

third row: d+5a e+5b f+5c

giving reasons for your answer

Answer 1

The first part of your question would be impossible to type showing each step because when I hit send, all the rows and columns will no longer line up. But there is hope. Go to YouTube and search for “ Determinants by cofactors”. There is a wonderful demonstration of a 4 by 4 matrix. Very detailed.

If we could connect through the whiteboard and do the problem there, it would not distort.

Good luck.

Linda