Answer:
-136
Step-by-step explanation:
We have to find the determinant of the following matrix:
![\left[\begin{array}{ccc}-4&5&6\\0&4&4\\-2&-5&4\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-4%265%266%5C%5C0%264%264%5C%5C-2%26-5%264%5Cend%7Barray%7D%5Cright%5D)
We can find the determinant by expanding via 1st column. i.e. by taking each element of 1st column and multiplying it by its co-factor matrix as shown below:
det
= ![(-4 \times det \left[\begin{array}{cc}4&4\\-5&4\end{array}\right]) - (0 \times (-4 \times det \left[\begin{array}{cc}5&6\\-5&4\end{array}\right]))+ ((-2) \times det\left[\begin{array}{cc}5&6\\4&4\end{array}\right])\\\\ =-4 \times (16 + 20)-(0)+(-2 \times 20-24)\\\\ =-4(36)+(-2(-4))\\\\ =-144+8\\\\ =-136](https://tex.z-dn.net/?f=%28-4%20%5Ctimes%20det%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D4%264%5C%5C-5%264%5Cend%7Barray%7D%5Cright%5D%29%20-%20%280%20%5Ctimes%20%28-4%20%5Ctimes%20det%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D5%266%5C%5C-5%264%5Cend%7Barray%7D%5Cright%5D%29%29%2B%20%28%28-2%29%20%5Ctimes%20det%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D5%266%5C%5C4%264%5Cend%7Barray%7D%5Cright%5D%29%5C%5C%5C%5C%20%3D-4%20%5Ctimes%20%2816%20%2B%2020%29-%280%29%2B%28-2%20%5Ctimes%2020-24%29%5C%5C%5C%5C%20%3D-4%2836%29%2B%28-2%28-4%29%29%5C%5C%5C%5C%20%3D-144%2B8%5C%5C%5C%5C%20%3D-136)
The notation det() stands for determinant of the matrix.
Therefore, the determinant of the given matrix is -136
Yes it is permitted area all has to do with that
Answer:
800 pennies
Step-by-step explanation:
Expression 2a + b represents the situation (total cost) of buying a apples and b bananas.
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Solution:
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Given that Daryl is buying apples and bananas.
He bought (a) pounds of apples that cost \$2 per pound.
He bought (b) pounds of bananas that cost \$1 per pound.
Need to write an expression which represents the situation.
Cost of 1 pound of apple = 2
\text { So cost of } a \text { pounds of apple }=a \mathrm{x} \text { Cost of } 1 \text { pound of apple }=a \mathrm{x} 2=2 a
Cost of 1 pound of banana =1
\text { So cost of } b \text { pounds of banana }=b \text { x Cost of } 1 \text { pound of banana }=b \times 1=b
Total cost of apples and banana = 2a + b
Hence, the required expression is 2a + b.
