BI 3 : Lng cu v lng cung ca loi hng ha X cc mc gi nh sau:P (nghn ng)Qd (n v)Qs ( n v)

1010040

129050

148060

167070

186080

205090

a. Vit phng trnh hm cung, cu. C nhn xt g v hnh dng ca ng cung cu , gii thch?PiQdi / QsiQdi.Pi / Qsi.PiPi2

10100 / 401000 / 400100

1290 / 501080 / 600144

1480 / 601120 / 840196

1670 / 701120 / 1120256

1860 / 801080 / 1440324

2050 / 901000 / 1800400

/ /

Vi PT hm s cu, ta c h PT : = n.a + b = a + b2 450 = 6a + 90b a = 150 6400 = 90a + 1420b b = -5=> PT hm s cu Qd = 150 5PVi PT hm s cung ta c h PT : = n.a + b = a + b2 390 = 6a + 90b a = -106200 = 90a + 1420b b = 5Vy hm s cung Qs = -10 + 5Pb. Hy xc nh im cn bng ca loi hng ha ny trn th trng? Vi iu kin Qs tng 45%, Qd gim 26%. V v th.Vi Qs tng 45% => Qs1 = Qs + 45% => Qs1 = (-10+5P)1,45 = -14,5 +7,25PVi Qd gim 26% => Qd1 = Qd -26% => Qd1 = (150-5P)0,74 = 111 3,7Piu kin cn bng th trng QE = Qd = Qs -14,5 + 7,25P = 111 3,7P 10,95P = 125,5 P = 11.461 => QE = 68,594Vy im cn bng E (11,461 ; 68,594)c. Gi s Chnh ph n nh gi l 45 n v tin. Theo bn th trng thiu ht hng ha hay khng?Khi Chnh ph n nh gi l 45 vtt thQd = 150 5.45 = -75Qs = -10 + 5.45215V Qs > Qd nn th trng s d tha hng had. Gi s Chnh ph n nh gi l 85 n v tin. Theo bn th trng thiu ht hng ha hay khng?e. Gi s gi th gii (Pw) l 55 n v tin. Theo bn nn nhp hay xut khu vi gi tr l bao nhiu?f. Gi s gi th gii (Pw) l 75 n v tin. Theo bn nn nhp hay xut khu vi gi tr l bao nhiu?