Answer: 

Step-by-step explanation:
- A null hypothesis is a hypothesis where a researcher generally try to disprove, it says that there is no statistically significant relationship between the two variables .
- An alternative hypothesis says that there is a statistical significance between two variables.
Claim 1. : Mean age of online dating service users is 40 years.
i.e.
, since it has equals sign so we take this as null hypothesis.
Claim 2. : Mean age of online dating service users is not 40 years.
⇒ Null Hypothesis : 
Alternative hypothesis : 
Area of a square is side length^2
Area = 15^ 2 = 15 x 15 = 225 square inches.
In this example, y is equal to 8.
In order to find this, first note that the two x value expressions create a straight line. That means when we add them together they will equal 180. this will give us a value for x.
x + 10 + 10x - 61 = 180
11x - 51 = 180
11x = 231
x = 21
Now that we have the value of x, we can do the same for the straight line created by the x + 10 angle and the 18y + 5 angle.
x + 10 + 18y + 5 = 180
(21) + 10 + 18y + 5 = 180
36 + 18y = 180
18y = 144
y = 8
The answer is C.
If Sergio is 'S' years old, and you want to know how old he'll be in 7 years, add 7 years to his age.
So: s + 7
Hope this helps!
If you would like to solve 2x + 5y = - 13 and 3x - 4y = -8, you can do this using the following steps:
<span>2x + 5y = -13 /*4
3x - 4y = -8 /*5
</span>_________________
8x + 20y = -52
15x - 20y = -40
_________________
8x + 15x + 20y - 20y = -52 - 40
23x = -92 /23
x = -92 / 23
x = -4
<span>2x + 5y = -13
</span>2 * (-4) + 5y = -13
-8 + 5y = -13
5y = -13 + 8
5y = -5
y = -1
(x, y) = (-4, -1)
The correct result would be D.) <span>(-4, -1).</span>