It is known that the eigenvalues of a matrix of order 3 are 2,1, - 1. Find the eigenvalues of a + 3E and calculate the determinant | a + 3E|

It is known that the eigenvalues of a matrix of order 3 are 2,1, - 1. Find the eigenvalues of a + 3E and calculate the determinant | a + 3E|

The eigenvalues of a + 3E are 2 + 3,1 + 3, - 1 + 3
So determinant: 5 * 4 * 2 = 40