- #1

- 21

- 0

## Homework Statement

find the determinant using row operations:

1 -2 2

0 5 -1

2 -4 1

## Homework Equations

## The Attempt at a Solution

i took row 3 and took 2 x row 1 away from it to get :

1 -2 2

0 5 -1

0 0 -3

1 x 5 x (-3) = -15...but i multiplied a row by 2 so i should get -30 for the det right?but the answer in my book is -15..what am i doing wrong?