This problem is Not Linear
Answer:
Here is a graph I created.
For Miguel to spend the least amount of money, he would have to buy 2 gallons for $5.98 and two 1/2 gallons for $4.20. The total is $10.18.
I'm stuck on the next question though.
4x = 32 - 2x
Add -2x (or subtract 2x) from each side
2x = 32
Divide both sides by 2
x = 16
Answer:

Step-by-step explanation:
Written in: y=mx+b
Answer:
12x^3 - 11x^2 + 9x + 18
Step-by-step explanation:
12x^3 - 20x^2 + 24x + 9x^2 -15x + 18
Combine like terms
12x^3 - 11x^2 + 9x + 18