Given two ordered (x,y) pairs that satisfy the equation, the standard path to the solution starts with plugging each set of x and y values in the general form to get two equations in the parameters a and b. For this example...
Then dividing one equation by the other eliminates parameter a, allowing you to solve for b:
Then you can plug this value of b into either original equation to solve for a.
I'll let you do the work. Since the value of b is the 5th root of 6, use a calculator....