To find the total amount Samuel spent at the market on both days, we can break down his purchases:
On the first day:
- He bought 3 pounds of apples at \( x \) dollars per pound: \[ 3x \]
- He bought 2 bags of spinach at \( y \) dollars each: \[ 2y \]
Thus, the total for the first day is: \[ 3x + 2y \]
On the second day:
- He bought 5 pounds of apples at \( x \) dollars per pound: \[ 5x \]
- He bought 3 bags of spinach at \( y \) dollars each: \[ 3y \]
Thus, the total for the second day is: \[ 5x + 3y \]
To find the total amount spent over both days, we add the two totals together: \[ (3x + 2y) + (5x + 3y) = 3x + 5x + 2y + 3y = 8x + 5y \]
So, the expression that represents the total amount he spent at the market on both days is: \[ \boxed{8x + 5y} \]