3. Given two IS equations as below. Y = 2500 - 600r and Y = 2500 - 1200r, a. Explain which curve is flatter. b. What is the factor that causes the slope of the IS curve to change? 4. Explain the relationship between the slope of the IS curve and the slope of the investment curve. 5 . Given the following information. C = 100 + 0.75 Ya , (dengan, Yd = Y - T) 1 = 240 - 600r G = 50 T = 30 a. Derive the equation for IS curve. b. Calculate the equilibrium level of income if the interest rate is 8 percent. C . What is the impact on the equilibrium level of income if the government runs an expansionary fiscal policy by adding G by 200 units? d. What is the impact on the IS curve if the government increases tax to 80 units? e. What are the factors other than the fiscal policy factors that can cause the IS curve to shift