Inverse of a matrix in R -

i trying find inverse of 3*3 matrix using solve in r.

>a=c(1:3)   >b=c(4:5)   >c=c(7:9)    >n=cbind(a,b,c)    [1,] 1 4 7   [2,] 2 5 8   [3,] 3 6 9    >det(n)   0    >solve(n)    lapack routine dgesv: system singular: u[3,3] = 0 

i dont understand , matrix's determinent 0 , numeric matrix. still gives singular matrix error.

can me this?

a matrix determinant 0 called singular , not invertible. means 1 or more of rows of matrix can made linear combinations of other rows. there no unique solution problem ax=b, matrix , b solution vector.