Remark
You'll see it a whole lot easier if you make a substitution so that it looks like something you have already seen
Solution
let y = x^2
x^4 = x^2 * x^2
x^4 = y * y
x^4 = y^2
Now the expression becomes
y^2 + 8 y - 9 = z
(y + 9)(y - 1) = z
Now put the x^2 back in.
(x^2 + 9) ( x^2 - 1) = z
x^2 - 1 becomes x + 1 and x - 1. At this level x^2 + 9 can't be factored.
Answer
(x^2 + 9) (x + 1)(x - 1)
Answer:

Step-by-step explanation:
we know that
The ratio of soil, manure and leaf mould is 
That means
For every 6 liters of the compost, he use 3 liters of soil
so by proportion
Find how many liters of soil does he use for 72 liters of compost

The slope of a linear equation will tell you the price of each ticket. The y-intercept tells you the convenience fee.
We can find the slope by choosing two points and finding the slope.
m = (y2 - y1)/(x2 - x1)
m = (887.40 - 231.15)/(20 - 5)
m = 656.25/15
m = 43.75
Each ticket will cost $43.75