Solve and simplify the steps

Question 9: In 2021 Germany had a GDP of about 4,26 trillion USD. The population was about 83 million. A. Calculate GDP per capita in 2021. -B. Suppose GDP grows at a rate of 1% and population at a rate of 0.4%, calculate GDP per capita in 2022. - C. Suppose both rates remain constant, when would GDP per capita reach 55 000 USD? Question 10: The profit obtained by producing x units of product A and y units of product B is approximated by the model P(x,y) = 8x + 10y 0.1(x? + xy + y') - 1000 Find the production level that produces a maximum profit Question 11: Solve the system of equations by using the augmented matrix: 2x + 4A = I12 2x + y + 3z =~ I -3y +z = 7 Question 12: Let x denote the level of output of a firm's production process. The cost function is given by C (x) = 0.8x(x -2)+100 and the demand function of the product by x =400 - Sp. (a) Compute profit E(x). (b) Find the output x at which profit is maximized