Find the characteristic polynomial of the matrix A=(2103)A = \begin{pmatrix} 2 & 1 \\ 0 & 3 \end{pmatrix}A=(2013)
λ2−5λ+6\lambda^2 - 5\lambda + 6λ2−5λ+6
λ2−5λ+5\lambda^2 - 5\lambda + 5λ2−5λ+5
λ2+5λ+6\lambda^2 + 5\lambda + 6λ2+5λ+6
λ2−3λ+2\lambda^2 - 3\lambda + 2λ2−3λ+2