交叉弹性

def solve(____):
    cross_elasticity = quantity_x_change / price_y_change
    if cross_elasticity > ____:
        relation = "____"
    elif cross_elasticity < ____:
        relation = "____"
    else:
        relation = "____"
    return {"____": price_y_change, "____": quantity_x_change, "____": cross_elasticity, "____": relation}