Answer:
Step-by-step explanation:
Let C(x) be the cost to produce x batches of widgets, and let R(x) be the revenue in thousands of dollars.

Profit function = Revenue - cost
So we get profit function by subtracting C(x) from R(x) using algebraic method of subtraction.
Profit function of x
= 
Answer:
He had 0.8 liters to start with...
Step-by-step explanation:
0.44 is 55% of what? (what = x)
Equation: Y = P% * X
X = Y/P%
X = 0.44/55%
55% = 0.55
X = 0.44/0.55
X = 0.8