Can you please show me how to solve this tutorial question, I am a bit unsure.

1. [Basic] Use the simple Keynesiancross model for a closed economy developed in our lecture to predict the impact of the following on equilibrium income (1\"). In each case: 0 state the direction of the change; a give a formula (Le. multiplier} for the size of the impact; a Illustrate your answer {regarding the direction of change of equilibrium output Q\") with an appropriate Keynesiancross diagram. Use the notations and model assumptions developed in Lecture 2. The scenarios as follows: (a*_] An increase in Planned Investment (AI > 0}