Answer:
5 bags of brand x and 6 bags of brand y.
Step-by-step explanation:
Nutrient requirement for the garden:
39 pounds of nutrient a and
16 pounds of nutrient b
Component of each bag of brand x:
3 pounds of nutrient a and 2 pounds of nutrient b
Therefore, 5 bags of brand x will contain 15 pounds of nutrient a and 10 pounds of nutrient b
Component of each bag of brand y:
4 pounds of nutrient a and 1 pound of nutrient b
Therefore, 6 bags of brand y will contain 24 pounds of nutrient a and 6 pounds of nutrient b
Altogether, she should buy 5 bags of brand x and 6 bags of brand y to meet the nutrient requirement of the garden
