# Matrices help please! (1 Viewer)

#### mattsteel87

##### New Member
Can anyone explain the following questions please:

1) For what value of k does the system of equations shown have no solution. (Use a matrix approach to the problem)

x + ky = 1
kx + y = 1

2) For which values of c does the system of equations shown have a solution? (This is best done using a matrix approach and you can use the internet to find the inverse of the 3 x 3 matrix to save some work if you want)

x - y - 3z = 3
2x . + z = 0
2y +7z = c

3) .

Thanks!

Last edited:

#### blyatman

##### Well-Known Member
You should be able to solve it by using the fact that a linear system is consistent (i.e. has solutions) if and only if the coefficient matrix and augmented matrix have the same rank. The rank of a matrix is simply the number of non-zero rows in its row echelon form.

#### realcareerchats

##### New Member
For no solutions the determinant has to be zero...which is ad-bc in the matrix of coefficients...so solve 1-k^2=0 to find values of K such that there are no solutions