I believe the correct answer from the choices listed above is option D. The statement that explains Karina's solution would be that the cost of natural gas is $0.83 per unit. Her solution was y=0.83 where y represents the cost of the natural gas. Hope this answers the question.
There are 1680 digits 2, 0, 2, and 2 as a 4-digit consecutively ordered block with no other digits between them
<h3>How to determine the selection</h3>
To determine the number of whole numbers, the following must be true
Case 1: If the sequence starts from the first digit
- The first digit can be any of the three 2's (i.e. 3 digits)
- The second digit can only be 0
- The third digit can be any of the remaining 2's (i.e. 2 digits)
- The fourth digit can only be the last 2 (i.e. 1 digit)
- The fifth digit can be any of 0 - 9 (i.e. 10 digits)
- The sixth digit can be any of 0 - 9 (i.e. 10 digits)
So, we have:


Case 2: If the sequence starts from the second digit
- The first digit can be any of 1 - 9 (i.e. 9 digits)
- The second digit can be any of the three 2's (i.e. 3 digits)
- The third digit can only be 0
- The fourth digit can be any of the remaining 2's (i.e. 2 digits)
- The fifth digit can only be the last 2 (i.e. 1 digit)
- The last digit can be any of 0 - 9 (i.e. 10 digits)
So, we have:


Case 2: If the sequence starts from the third digit
- The first digit can be any of 1 - 9 (i.e. 9 digits)
- The second digit can be any of 0 - 9 (i.e. 10 digits)
- The third digit can be any of the three 2's (i.e. 3 digits)
- The fourth digit can only be 0
- The fifth digit can be any of the remaining 2's (i.e. 2 digits)
- The last digit can only be the last 2 (i.e. 1 digit)
So, we have:


The total number of whole numbers is:


Hence, there are 1680 6-digit whole numbers that the digits
Read more about combination and permutation at:
brainly.com/question/2292449
<span><span>(<span>sinx</span>−<span>tanx</span>)</span><span>(<span>cosx</span>−<span>cotx</span>)</span></span>
<span>=<span>(<span>sinx</span>−<span><span>sinx</span><span>cosx</span></span>)</span><span>(<span>cosx</span>−<span><span>cosx</span><span>sinx</span></span>)</span></span>
<span>=<span>sinx</span><span>(1−<span>1<span>cosx</span></span>)</span><span>cosx</span><span>(1−<span>1<span>sinx</span></span>)</span></span>
<span>=<span>sinx</span><span>(<span><span>cosx</span><span>cosx</span></span>−<span>1<span>cosx</span></span>)</span><span>cosx</span><span>(<span><span>sinx</span><span>sinx</span></span>−<span>1<span>sinx</span></span>)</span></span>
<span>=<span><span>sinx</span><span>cosx</span></span><span>(<span>cosx</span>−1)</span><span><span>cosx</span><span>sinx</span></span><span>(<span>sinx</span>−1)</span></span>
<span>=<span>(<span>cosx</span>−1)</span><span>(<span>sinx</span>−1<span>)</span></span></span>
Answer:
Step-by-step explanation:
x^2-19x-20
=x^2-(20-1)x-20
=x^2-20x+x-20
=x(x-20)+1(x-20)
=(x-20)(x+1)