A showing calculation is needed

2 (a) Diberikan fungsi permintaan Given the demand function Q1 = 100 - P1 + 0.75P2 - 0.25P3 + 0.0075Y di mana where P1 = 10, P2 = 20, P3 = 40 and Y = 10000, Q1 = 170. i) Carikan keanjalan prmintaan bersilang dan komen atas hubungan antara barangan 1 dengan dua barangan yang lain. Find the cross price elasticities of demand and comment on the relationship between good 1 and other two goods. (4 markah/marks) ii) Tentukan kesan ke atas Q1 akibat peningkatan harga sebanyak 10 peratus untuk setiap barangan berlainan. Determine the effect on Q1 of a 10 percent price increase for each of the other goods individually. (4 markah/marks) iii) Tentukan keanjalan permintaan pendapatan. Anggarkan peratusan perubahan permintaan apabila pendapatan meningkat sebanyak 5% dan komen atas potensi pertumbuhan barangan ini dalam ekonomi yang berkembang. Determine the income elasticity of demand. Estimate the percentage change in demand when income rises by 5% and comment on the growth potential of this good in an expanding economy. (2 markah/marks) (b) Diberikan fungi utiliti u = Ax y tertaluk kepada kekangan bajet Pxx + Pyy = B, buktikan bahawa pada titik kekangan utiliti maksimum, nishah harga Px/Py mesti sama dengan nisbah marginal utilities. Given the utility function u = Axy subject to the budget constrant Pxx + Pyy = B, prove that at the point of constrained utility maximisation the ratio of prices PUP must equal the ratio of marginal utilities MU./MU. (5 markah/marks)