How to calculate the second part

step by step and explain thx

Therefore, the utility function becomes (for A = 3.5): U = 0.08 - 0.10 xy - 12 * 3.5 (yx 0.28)? x = 0.08 - 0.10 x y-0.1372 x y? To solve for the maximum utility, take the derivative with respect to y of the equation and set it equal to zero: 0 = -0.10 -2 * 0.1372 x y = -0.10 -0.2744 x y Therefore, y is equal to: -0.10 -0.2744 = 36.4% The client has 36.4% in the risky portfolio and 63.6% in the risk-free asset