<h3>Answer: B) $878.28</h3>
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Explanation:
She starts off $16.75 in debt
Later on she deposits $16.75 to get completely out of debt and make the balance 0. This is after depositing the $5.72
So far her balance is $5.72
Add on $872.56 to get 5.72+872.56 = 878.28
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This is what your steps may look like
-16.75 + (5.72 + 16.75)
-16.75 + (16.75 + 5.72)
(-16.75+16.75) + 5.72
(0) + 5.72
5.72
5.72+872.56
878.28
Answer:
It will take nine years and four months for the refrigerator to pay for itself.
Step-by-step explanation:
The new refrigerator which costs $1200, saves the family 22% annually in energy cost.
Since the old refrigerator costs $580 to run, we want to determine how many years it will take for 22% of $580 per year to make $1200.
22% of $580
= 580 × 0.22
= 127.6
That is, it saved then $127.6 per year.
Now,
$1200/127.6
≈ 9.4
Which means, it will take 9 years and 4 months for the refrigerator to pay for itself.
Answer:
the lower right matrix is the third correct choice
Step-by-step explanation:
Your problem statement shows that you have correctly selected the matrices representing the initial problem setup (middle left) and the problem solution (middle right).
Of the remaining matrices, the upper left is an incorrect setup, and the lower left is an incorrect solution matrix.
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We notice that in the remaining matrices on the right that the (2,3) term is 0, and the (3,2) and (3,3) terms are both 1.
The easiest way to get a 0 in the 3rd column of row 2 is to add the first row to the second. When you do that, you get ...
![\left[\begin{array}{ccc|c}1&1&1&29000\\1+2&1-3&1-1&1000(29+1)\\0&0.15&0.15&2100\end{array}\right] =\left[\begin{array}{ccc|c}1&1&1&29000\\3&-2&0&30000\\0&0.15&0.15&2100\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%261%261%2629000%5C%5C1%2B2%261-3%261-1%261000%2829%2B1%29%5C%5C0%260.15%260.15%262100%5Cend%7Barray%7D%5Cright%5D%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%261%261%2629000%5C%5C3%26-2%260%2630000%5C%5C0%260.15%260.15%262100%5Cend%7Barray%7D%5Cright%5D)
Already, we see that the second row matches that in the lower right matrix.
The easiest way to get 1's in the last row is to divide that row by 0.15. When we do that, the (3,4) entry becomes 2100/0.15 = 14000, matching exactly the lower right matrix.
The correct choices here are the two you have selected, and <em>the lower right matrix</em>.