For what values of a does the system below have nontrivial s

For what values of a does the system below have nontrivial solutions?

a) 4

b) -2

c) 8

d) -8

e) -4

f) None of the above.

Solution

On a = -8, the system below have nontrivial solutions.

because on a = -8 ,, first two equation have same with constant multiple 4.