Find the characteristic polynomial of the matrix I redid my

Find the characteristic polynomial of the matrix

I re-did my calculations twice to make sure then I used an online calculator to see if I had made a mistake and I got the same answer but my answer is incorrect, why?

Entered The answer above is NOT comecl. (1 point Find tho characteristc polynomial of the matrix A 52 Answer Preview Result

Solution

The characteristic polynomial of A is det(A-I₃) = (2-)[(-5-)(-) –(-2)(1)] -1[0*(-)-2] or, (2-)[(+5)+2] +2 or, (2-)(² +5+2)+2 or, 2² +10 +4 –³ -5² -2 +2 or, –³-3 ²+8+6