The only value of b for which the following system of equations in(s,u,z)does not have a unique solution is: b =

Question

3⁢s+3⁢u-z=3
-3⁢s+3⁢u=-3
-3⁢s+b⁢u-z=-3

Answer 1

form a matrix of the coefficients
3 3 -1
-3 3 0
-3 b -1

take the determinant,
I got 3b - 27

for no solution, that determinant will have to be zero
so
3b - 27 = 0
b = 9