If you need help solving from that edition legally (by posting the full problem text without solutions), I can walk you through the reasoning. Just share one problem at a time.
Macroeconomic models require algebraic manipulation (e.g., solving for equilibrium income, deriving multipliers, or finding the slope of the LM curve). Without step-by-step validation, a single algebraic error can cascade through an entire problem. Dornbusch Fischer Macroeconomics 6th Edition Solutions