Answer:

Step-by-step explanation:
Given

Required
Determine the solution
Since b is a perfect square, the equation can be expressed as:

Apply difference of two squares:

Split:

Remove brackets:

Make a the subject in both equations

The solution can be represented as:

Answer:
Which one?
Step-by-step explanation:
4n² - 16n - 84 = 0
Multiply both sides by 1/4 :
n² - 4n - 21 = 0
Add 21 to both sides:
n² - 4n = 21
Complete the square by adding 4 to both sides:
n² - 4n + 4 = 25
(n - 2)² = 25
Solve for n :
n - 2 = ± √25
n - 2 = ± 5
n = 2 ± 5
Then n = 2 + 5 = 7 or n = 2 - 5 = -3.
Answer:
Option 2: 
Step-by-step explanation:
Given:
From the triangle shown below;
A triangle QRS with angle QRS = 90°, ∠QSR = 30°.
Side QR = 5, SQ = 10 and RS = 5√3
Now, we know from trigonometric ratio that,

Here, opposite side of angle QSR is QR and Hypotenuse is the side opposite angle QRS which is SQ. Therefore,

Therefore, the value of sine of 30° is one-half. So, second option is correct.
Answer:
f(g(x))(-1) = 0
Step-by-step explanation:
Step 1: Find f(g(x))
5(x + 3) - 10
5x + 15 - 10
5x + 5
Step 2: Plug in -1
5(-1) + 5
-5 + 5
0