7. Determine the rank of the following matrices by reducing to row echelon form. 0 2 20 1 2 1 0 (a) 2 48 6 (b) 3 6 6 3 1 32 262 3 9 1 4 1 6 2 10 6 1 x X 8. Find all such that the rank of the matrixx 1 X is less than 3. X X 1 9. Find the value of k for which the system of equations has a non-trivial solution. x+2y+z = 0 2x+y+3z0 x+ky+3z= 0 10. Solve the system of equations in integers x+2y+z = 1 3x+y+2z3 x + 7y+2x=1