Can someone please show me how to take the first order conditions of equation (7)? I don't understand how my teacher got equation (8).

Equation (6): max (y) [vi (yo) + 6:E [vi(y)] (yo -wo) +> as (ys-Ws) S 0] When we take the Lagrangean of equation (6) we get equation (7): Equation (7): max (y) [vi (yo) + S;E [vi(y)] - 1 (yo -wo) +E as (ys -Ws) _ 0] When we take the first order conditions in respect to yo (where you take ) to the right hand-side and then divide everything by 1), we end up with equation (8): Equation (8): 1/ Zi avi (yo (i)) / a yo (i) = 1 and di/ li avi (ys (i)) / a ys (i) = as/ Is