Division matrix

[Cleuson Alves]

Hello, I need to solve an exercise follows, first calculate the inverse matrix and then multiply the first matrix.
I await help.
Thank you.
follows the code below incomplete.

m = [[1,2,3],[4,5,6],[7,8,9]]
x = []
for i in [0,1,2]:
    y = []
    for linha in m:
        y.append(linha[i])
    x.append(y)

print x
[[1, 4, 7], [2, 5, 8], [3, 6, 9]]

def ProdMatrix(x,b):
    tamL = len(x)
    tamC = len(x[0])
    c = nullMatrix(tamL,tamC)
    for i in range(tamL):
        for j in range(tamC):
            val = 0
            for k in range(len(b)):
                val = val + x[i][l]*b[k][j]
            c[i][j]
    return c