Answer:
B
Step-by-step explanation:
![~~~2x^{16} - 32x^4\\\\ = 2x^4(x^{12} -16)\\\\=2x^4\left[(x^6)^2 - 4^2 \right]\\\\=2x^4(x^6 -4)(x^6 +4)~~~~~~~~~~~~~~~~~~;[a^2 -b^2 = (a+b)(a-b)]\\\\=2x^4\left[(x^3)^2 - 2^2\right] (x^6 +4)\\\\=2x^4(x^3 -2)(x^3 +2)(x^6 +4)](https://tex.z-dn.net/?f=~~~2x%5E%7B16%7D%20-%2032x%5E4%5C%5C%5C%5C%20%3D%202x%5E4%28x%5E%7B12%7D%20-16%29%5C%5C%5C%5C%3D2x%5E4%5Cleft%5B%28x%5E6%29%5E2%20-%204%5E2%20%5Cright%5D%5C%5C%5C%5C%3D2x%5E4%28x%5E6%20-4%29%28x%5E6%20%2B4%29~~~~~~~~~~~~~~~~~~%3B%5Ba%5E2%20-b%5E2%20%3D%20%28a%2Bb%29%28a-b%29%5D%5C%5C%5C%5C%3D2x%5E4%5Cleft%5B%28x%5E3%29%5E2%20-%202%5E2%5Cright%5D%20%28x%5E6%20%2B4%29%5C%5C%5C%5C%3D2x%5E4%28x%5E3%20-2%29%28x%5E3%20%2B2%29%28x%5E6%20%2B4%29)
<u>Answer:</u>
The expression that can be used to determine how fast an elephant runs in miles per hour is 100 miles per hour
<u>Solution:</u>
Given that,
Distance covered by an elephant in 36 seconds is equal to 1 mile
Therefore, <em>distance covered by the elephant in 1 second</em> is
mile
Therefore, <em>distance covered by the elephant in 60 seconds</em> (60 seconds = 1 minute) is

Therefore, <em>distance covered by the elephant in 60 minute</em> (60 minute = 1 hour) is

Hence the expression that can be used to determine how fast an elephant runs in miles per hour is 100 miles per hour
First translate the English phrase "Four times the sum of a number and 15 is at least 120" into a mathematical inequality.
"Four times..." means we're multiplying something by 4.
"... the sum of a number and 15..." means we're adding an unknown and 15 and then multiplying the result by 4.
"... is at least 120" means when we substitute the unknown for a value, in order for that value to be in the solution set, it can only be less than or equal to 120.
So, the resulting inequality is 4(x + 15) ≤ 120.
Simplify the inequality.
4(x + 15) ≤ 120
4x + 60 ≤ 120 <-- Using the distributive property
4x ≤ 60 <-- Subtract both sides by 60
x ≤ 15 <-- Divide both sides by 4
Now that we have the inequality in a simplified form, we can easily see that in order to be in the solution set, the variable x can be no bigger than 15.
In interval notation it would look something like this:
[15, ∞)
In set builder notation it would look something like this:
{x | x ∈ R, x ≤ 15}
It is read as "the set of all x, such that x is a member of the real numbers and x is less than or equal to 15".