If the expression \( 3a + 5b \) evaluates to 41 when \( a = 4 \) and \( b = x \), and the expression \( 2a - b \) evaluates to 10 when \( a = y \) and \( b = 3 \), determine the values of \( x \) and \( y \). Let's think step by step and output the final answer within \boxed{}.
user