If the system of equations 2x - y = a, 3y - 6x = b has a solution, find a / b, assuming b is not equal to 0.

\(2x - y = a\\ -6x+3y=b\\ \text{Add 3 times equation 1 to equation 2}\\ 0=3a+b\\ b = -3a\\ \dfrac a b = \dfrac{a}{-3a} = -\dfrac 1 3\)

Thanks for the help!