To find the amount of seed Susan needs to plant 34.6 acres of land, you can use the given rate of 3.5 pounds of seed per acre. Simply multiply the number of acres by the rate:
Seed needed = Acres × Seed per acre
Seed needed = 34.6 acres × 3.5 pounds/acre
Seed needed = 120.1 pounds
Susan needs 120.1 pounds of seed to completely plant her 34.6 acres of land.