Considere as matrizes !$ A = ( \alpha_{ij})_{ 3x3} !$, definida por !$ \alpha_{ij} = { \begin{cases} i^{-1},se\,i < j\\i + j, se\,i=j,\\j^2 -1, se\,i>\,j \end{cases}} !$ e !$ B = { \begin {pmatrix} x\,\,-x\,\,3\,\,0\\0\,\,\,1\,\,\,x\,\,-1\\0\,\,\,\,0\,\,\,\,5\,\,\,\,2\\0\,\,\,\,0\,\,\,\,0\,\,\,\,x \end{pmatrix}} !$
Qual(ais) o(s) valor(es) de x que satisfaz(em) a equação !$ det A = det B !$?
