Labour. They are man-made and used in agriculture.
Step-by-step explanation:
use desmos it's a graphing calculator just put in the equation
Answer:
god loves you <3 .
Step-by-step explanation:
Because if let's say you have 400$ for the year, and each book cost 10$. So it would be written as 400-10b since the quantity of books must be multiplied times their cost to calculate whether you are within or outside the budget.