我觉得应该是GDP=(40-10-12)*10=180
麻烦您再费心教教我

Alabama和California（CA）都是美国的州，级别相当于中国的省份
GDP有生产法、收入法、支出法三种核算方法，宏观里常用的支出法核算，GDP=C+I+(X-M)，有进口和出口问题
其他两种，跟进出口无关。三种核算理论上等价，但是不代表三者可以混着计算

非常感谢！

还有一题，我觉得我做的也不对，麻烦您也帮我看看好吗？总算遇到高人了，非常感谢了！
The following equations describe the macro economy of Country A.  Assume that
     GDP and GNI are equal.  They are denoted Y.  Throughout the question we will
     assume that there is full employment, so that Y is fixed.  The interest rate (r) is
     expressed in percent.  Use the information to answer the questions below.  (16 pts)

                Y = 5000
                C = 800 + .75(Y-T) – 100r
                 I = 825 – 50r
                G = 600, T = 400


        a.  If Country A has a closed financial system with respect to the rest of the world
                 (i.e., doesn’t allow borrowing or lending with other countries), what will the
                 interest rate be in Country A?  How much domestic investment spending (I)
                 will there be?  (Hint:  You will find it helpful to derive the national saving
                 function using S = Y – C – G).
Country A has a closed financial system,  
C = 800 + .75(Y-T) – 100r=4250-100r
Y=C+I+G=4250-100r+(825-50r)+600=5000  →r=4.5  the interest rate be 4.5%
              I = S= Y – C – G=5000-(4250-100r)-600=600     
        b.  Continuing to assume that the financial system is closed, suppose that in an
                 effort to balance the government budget, government consumption
                 expenditures (G) are reduced from 600 to 400.  What will the new interest rate
                 be?  What will happen to investment spending?   

        Country A has a closed financial system,  
Y=C+I+G=4250-100r +(825-50r)+400=5000  →r=3.17

                     I = S= Y – C – G=5000-(4250-100r)-400=666.5

        c.  Go back to the original equations and conditions of the problem (with G equal
                 to 600) but assume that Country A has an open capital market and is perfectly
                 integrated with a world financial system whose interest rate is 3%.  Assume
                 that Country A is relatively small in the world, so that developments inside of
                 Country A have a negligible effect on the world interest rate.  Will Country A
                 have net capital inflow or outflow?  In what amount?  How much investment
                 spending will there be?
                     
                       Country A has a open financial system,
Country A will have net capital inflow
                     X-M= Y-(C+I+G)=5000-(4250-100*3+825-50*3+600)=-225

                   I = 825 – 50r=825-50*3=675

        d.  Continue with the situation described in part (c), where the country is part of a
                 large global financial system, and reconsider the effects of reducing
                 government spending to 400.  What will happen to the country’s net capital
                 flows?  What will the new level of domestic investment spending be?

                      Country A has a open financial system,
                     X-M=(IP-IR)+(KO-KI)= (IP-IR)+(S-I) →
(KO-KI)= (S-I)= Y-(C+I+G)=5000-(4250-100*3+825-50*3+400)=-25   

ding
kankan