This system originates from systems of linear Diff Eqs. I am required to use the method of undetermined coefficients. -a2 + 5b2 - a1 = 0 -a2 + b2 -b1 -2 = 0 -a1 + 5b1 +a2 + 1 = 0 -a1 + b1 + b2 = 0 I can't figure out how I am able to solve this. In each case, I have two equations and three unknowns. I know the system is correct. The answers are: a2 = -3, b2 = -2/3, a1 = -1/3, b1 = 1/3. Thanks in advance.