Nakato, a south asian country, exported goods worth $500 million and imported goods worth $400 million in the last fiscal year. the country also made foreign investments worth $300 million and provided foreign aid worth $100 million in disaster relief. besides this, the country took a loan of $5 billion from the world bank. this flow of money into and out of nakato is measured by

David consumes two things: gasoline (g) and bread (b). david's utility function is u(g, b) = 10g^0.25 b^0.75. use the lagrange technique to solve for david's optimal choices of gasoline and bread as a function of the price of gasoline, p_g, the price of bread, p_b, and his income m. with recent decrease in the price of gasoline (maybe due to external shock such as shale gas production) does david increase his consumption of gasoline? for david, how does partial differential g/partial differential p_g depend on his income m? that is, how does david's change in gasoline consumption due to an increase in the price of gasoline depend on his income level? to answer these questions, find the cross-partial derivative, |partial differential^2 g/partial differential m partial differential p_g.