So focusing on x^4 + 5x^2 - 36, we will be completing the square. Firstly, what two terms have a product of -36x^4 and a sum of 5x^2? That would be 9x^2 and -4x^2. Replace 5x^2 with 9x^2 - 4x^2: 
Next, factor x^4 + 9x^2 and -4x^2 - 36 separately. Make sure that they have the same quantity inside of the parentheses: 
Now you can rewrite this as
, however this is not completely factored. With (x^2 - 4), we are using the difference of squares, which is
. Applying that here, we have
. x^4 + 5x^2 - 36 is completely factored.
Next, focusing now on 2x^2 + 9x - 5, we will also be completing the square. What two terms have a product of -10x^2 and a sum of 9x? That would be 10x and -x. Replace 9x with 10x - x: 
Next, factor 2x^2 + 10x and -x - 5 separately. Make sure that they have the same quantity on the inside: 
Now you can rewrite the equation as
. 2x^2 + 9x - 5 is completely factored.
<h3><u>Putting it all together, your factored expression is

</u></h3>
So you know the merchant made a 15% profit on the pen, so she bought it for a cheaper price. To find the cost of the pen before you have to take the price now, $6.90 and times it by 85%. You do 85% because you subtract the 15% she saved from 100% and you get 85%. So 6.90x.85= 5.865 which rounds to $5.87
Answer:
a) $3480
b) $4036.8
Step-by-step explanation:
The compound interest formula is given by:

Where A(t) is the amount of money after t years, P is the principal(the initial sum of money), r is the interest rate(as a decimal value), n is the number of times that interest is compounded per year and t is the time in years for which the money is invested or borrowed.
Suppose that $3000 is placed in an account that pays 16% interest compounded each year.
This means, respectively, that 
So



(a) Find the amount in the account at the end of 1 year.
This is A(1).


(b) Find the amount in the account at the end of 2 years.
This is A(2).

Answer:
A. 0.5
B. 0.32
C. 0.75
Step-by-step explanation:
There are
- 28 students in the Spanish class,
- 26 in the French class,
- 16 in the German class,
- 12 students that are in both Spanish and French,
- 4 that are in both Spanish and German,
- 6 that are in both French and German,
- 2 students taking all 3 classes.
So,
- 2 students taking all 3 classes,
- 6 - 2 = 4 students are in French and German, bu are not in Spanish,
- 4 - 2 = 2 students are in Spanish and German, but are not in French,
- 12 - 2 = 10 students are in Spanish and French but are not in German,
- 16 - 2 - 4 - 2 = 8 students are only in German,
- 26 - 2 - 4 - 10 = 10 students are only in French,
- 28 - 2 - 2 - 10 = 14 students are only in Spanish.
In total, there are
2 + 4 + 2 + 10 + 8 + 10 +14 = 50 students.
The classes are open to any of the 100 students in the school, so
100 - 50 = 50 students are not in any of the languages classes.
A. If a student is chosen randomly, the probability that he or she is not in any of the language classes is

B. If a student is chosen randomly, the probability that he or she is taking exactly one language class is

C. If 2 students are chosen randomly, the probability that both are not taking any language classes is

So, the probability that at least 1 is taking a language class is

Step-by-step explanation:
Given inequality is
.
To graph that inequality, first we need to graph the line
. Then shade it for the inequality symbol <.
Graphing line can be done using two points.
plug x=0 into
, we get:

Hence first point is (0,2)
Similarly plug any random number for x say x=4, we get:

Hence first point is (4,5).
Now we just need to graph both points and join them by a dotted line. because we have < not <=.
Next part is to test for shading.
Which can be done using any test point which is not on the given line. Say (0,0)
plug x=0,y=0 into
.


0<2
which is true, hence shading will be in direction of test point (0,0).
Hence final answer will be the choice which looks like the graph attached below;