You need to show what a and b are plz
1. Consider right triangle ABK. In this triangle AB is the hypotenuse, BK and AK are legs. By the Pythagorean theorem,

2. Use the definition of 

Then 
3. Consider right triangle ABD. In this triangle AD is the hypotenuse, AB and BD are legs. Since
then

The leg that is opposite to the angle of 30° is half of the hypotenuse, so

4. The area of parallelogram aBCD is

I'm guessing your problem is this:
y³ - 9y² + y - 9 = 0
right?
In solving this problem, I recommend doing this:
y³ - 9y² + y - 9 = 0
Factor out a y² from the first two numbers in the problem:
y²(y - 9) + (y - 9) = 0
Separate the parentheses which means y - 9 goes on one side. The y² added a one since it came from the + 1 in the middle of expression. When you're separating parentheses like this you just take the outside numbers and combine them together. Since + 1 came from the outside of the (y - 9) and y² also was sitting on the outside of (y - 9) combine them to make y² + 1. Like this:
(y² + 1)(y - 9) = 0
Now separate your two parentheses to two separate problems:
(y² + 1) = 0 and (y - 9) = 0
Now you're y² + 1 will equal:
y² = -1
y = √-1 <-- This number doesn't exist so it will be an imaginary number (i). If you guys didn't learn that in your class I recommend just leaving it as i for that part.
Now solve y - 9 = 0:
y = 9 <-- Since we added nine to both sides to get this.
So you're final answer should be y = i and 9
Let one of the numbers be x. The other number cab then be represented as 36-x (x+36-x = 36).
The product can then be represented as y = x(36-x) or y=36x-x2
The maximum or minimum is always on the axis of symmetry which has the formula x=-b/2a.
In our case, the axis of symmetry is -36/-2, so x=18.
If one number is 18 and the 2 numbers add to 36, the other number is 18 as well.
So the 2 numbers are 18 and 18 and the maximum product is 324,
$16x.15=$2.40
16+2.4=18.40 the answer is $18.40
Hopefully this is helpful.