Step-by-step explanation:
so, we just enter the given data into the given formula. and then calculate. it does not get easier than that.
d = 8km/h × 2h = 16km
Serena ran 16km in these 2 hours.
For this case we have the following data:


So that the figure can be a rectangle, its diagonals must be equal, that is, 
In this way we have:

Clearing x we have:


Thus, x must be equal to 10 so that the figure is a rectangle.
Answer:

Option A
Answer:
Reject H0
Step-by-step explanation:
Given :
H0: The frequencies are equal. H1: The frequencies are not equal
Category f0 A 10 B 30 C 30 D 10
Total f0 = (10 + 30 + 30 + 10) = 80
Expected frequency is the same for all categories :
Expected frequency = 1/4 * 80 = 20
χ² = Σ(observed - Expected)² / Expected
χ² = (10-20)^2 / 20 + (30-20)^2 /20 + (30-20)^2 / 20 + (10-20)^2 / 20
χ² = (5 + 5 + 5 + 5) = 20
Pvalue = 0.00017
Pvalue < α
Order of operations are:
<span>1. Parentheses (simplify inside 'em)
2. Exponents
3. Multiplication and Division (from left to right)
<span>4. Addition and Subtraction (from left to right)
So, on your first one:
Parentheses first:8(3+4)-2*8/(5-3)
8(7)-2*8/(2)
There are no exponents so multiplication and division:56-16/2
56-8
Finally, addition and subtraction:56-8=48
Your second problem is a bit more complicated but follows the same rules:
</span></span>

<span><span>
Parentheses first:</span></span>

<span><span>
Now, exponents. Even though they are inside parentheses, we can't go further until we simply those.
(64+81)/5
Now back to parentheses:(145)/5
Division:
145/5=29
Hope that helps</span></span>