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2 years ago

11 th grade algebra .

Mathematics

1 answer:

Ksju [112]2 years ago

7 0

Answer:

Step-by-step explanation:

The inverse of a matrix is the transpose of the cofactor matrix, divided by the determinant. The determinant is (4)(3) -(1)(-5) = 17, eliminating choice B.

In a 2×2 matrix, the transpose of the cofactor matrix swaps the diagonal elements, and negates the off-diagonal elements. That is, the transpose of the cofactor matrix will look like the matrix of B. When that is divided by 17, you get the matrix of answer choice C.

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$9-8x\geq0\ \ \ |subtract\ 9\ from\ both\ sides\\\\-8x\geq-9\ \ \ \ |change\ signs\\\\8x\leq9\ \ \ \ |divide\ both\ sides\ by\ 8\\\\x\leq9\\\\ |9-8x|=\left\{\begin{array}{ccc}9-8x&for\ x\leq9\\8x-9&for\ x \ \textgreater \ 9\end{array}\right$

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2 years ago

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Papessa [141]

Answer:

A bicycle store installs about 400 tires per day. Tires are installed Monday through Friday for 8 hours per day. The owner of the store estimates the number of properly installed tires per week using the process below.

In the first hour of work on Monday, 49 out of 50 tires were properly installed.

So, there were about 8(49) = 392 properly installed tires on Monday.

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The results are likely invalid because it is unlikely that the tires installed in one hour on Monday will represent the entire population of tires.

The results are likely invalid because the entire population during one week was not part of the sample.

<u>The results are likely valid because a large number of tires produced during the week were part of the sample. </u>

The results are likely valid because each tire sampled was part of the population of tires that week.

Step-by-step explanation:

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