Suppose that in a two-sector economy with only households and enterprises, consumption C = 100+ 0.8Y, investment I = 150-6R, money supply M =150, and money demand L= 0.2Y-4R (both units are in the hundreds of millions of dollars.

(1) Calculate IS and LM curves

(2) to find the interest rate and income when commodity market and money market are in equilibrium simultaneously;