The following difference equation describes a simple model of a certain economy, where upper y subscript k is the total income during year k, a is a constant less than 1, called the marginal propensity to consume, and b is a positive constant of adjustment that describes how changes in consumer spending affect the annual rate of private investment. upper y subscript k plus 2 baseline minus a left parenthesis 1 plus b right parenthesis upper y subscript k plus 1 baseline plus aby subscript kequals6 find the general solution when aequals0.6 and bequalsone sixth . what happens to upper y subscript k as k increases? [hint: first find a particular solution of the form upper y subscript kequalst, where t is a constant, called the equilibrium level of national income.]