Answer:
The answer is below
Step-by-step explanation:
Let x represent the amount of iron, y represent the amount of potassium and z represent the amount of mulch.
Since the supplement weighs 16 lb, hence:
x + y + z = 16 (1)
Also supplement contains thirteen times as much mulch as iron. Therefore:
x = 13z
x - 13z = 0 (2)
The supplement also has twice as much potassium as iron, hence:
x = 2y
x - 2y = 0 (3)
solving equations 1, 2 and 3 simultaneously gives:
x = 10.1 lb, y = 5.1 lb, z = 0.8 lb
This means that the soil supplement contains 0.8 lb of mulch
