The economy of Sunrise Island has the following features: ' xed price level ' no foreign trade ' autonomous desired investment (I) of $20 billion ' autonomous government purchases (G) of $30 billion ' autonomous desired consumption (c) of $10 billion ' marginal propensity to consume out of disposable income of 0.90 ' net tax rate of 0.40 of national income a. Write an equation expressing consumption as a function of disposable income. Write the constant values in billions of dollars. C=D+DYEJ (Round your response for the intercept to the nearest whole number, and round your response for the slope to two decimal places.)