$An\ idempotent\ matrix\ is\ a\ matrix\ n\times n\ (square\ matrix\ A)\ which:A^2=A\\\\Example:\\ A=\left[\begin{array}{ccc}2&-1\\2&-1\end{array}\right]\\A^2=\left[\begin{array}{ccc}2&-1\\2&-1\end{array}\right]\cdot\left[\begin{array}{ccc}2&-1\\2&-1\end{array}\right]=\left[\begin{array}{ccc}2\cdot2-1\cdot2&2\cdot(-1)-1\cdot(-1)\\2\cdot2-1\cdot2&2\cdot(-1)-1\cdot(-1)\end{array}\right]\\= \left[\begin{array}{ccc}4-2&-2+1\\4-2&-2+1\end{array}\right] = \left[\begin{array}{ccc}2&-1\\2&-1\end{array}\right] =A$

7 0

3 years ago

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Evaluate each expression using order of operations <br><br>40-32÷8+5×-2

klio [65]

Answer:

Step-by-step explanation:

40-32÷8+5×-2

40-4+5×-2

40-4+-10

36+-10

6 0

2 years ago

Number 2 is the problem i need help with

Reptile [31]

Answer:

2a) $180

2b) $1440

Step-by-step explanation:

2a) Basically Samuel works for 6 hours a day and earns 7.50 per hour, so you have to do 7.50 x 6 to see how much he earns per day (which in this case is $45). You then have to multiply $45 to 4 since he earns $45 per day and works 4 days per week (which is $180).

2b) After finding out how much he earns per week ($180 from the previous question), you then have to multiply $180 by 8 as $180 is the amount he earns per week and since he works for 8 weeks you have to multiply $180 by 8 (the answer is then $1440).

sorry if I'm not making sense, i tried :) good luck!

8 0

3 years ago

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