To determine the total amount Samuel spent at the farmers market over both days, we need to analyze his purchases.
First day:
- He bought 1 pound of apples for \(x\) dollars per pound: \(1 \times x = x\) dollars.
- He bought 3 bags of spinach for \(y\) dollars each: \(3 \times y = 3y\) dollars.
- Total spent on the first day: \(x + 3y\).
Second day:
- He bought 6 pounds of apples for \(x\) dollars per pound: \(6 \times x = 6x\) dollars.
- He bought 2 bags of spinach for \(y\) dollars each: \(2 \times y = 2y\) dollars.
- Total spent on the second day: \(6x + 2y\).
Total spent over both days:
- Combine both totals: \[ (x + 3y) + (6x + 2y) = (x + 6x) + (3y + 2y) = 7x + 5y. \]
So, the expression that represents the total amount he spent at the market on both days is: \[ \boxed{7x + 5y}. \]