Answer:
![\left[\begin{array}{ccc}-30&22&8\\-4&-4&16\\30&-28&18\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-30%2622%268%5C%5C-4%26-4%2616%5C%5C30%26-28%2618%5Cend%7Barray%7D%5Cright%5D)
Step-by-step explanation:
Given
![A = \left[\begin{array}{ccc}-1&9&2\\10&-10&2\\-5&6&-5\end{array}\right]](https://tex.z-dn.net/?f=A%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-1%269%262%5C%5C10%26-10%262%5C%5C-5%266%26-5%5Cend%7Barray%7D%5Cright%5D)
![B = \left[\begin{array}{ccc}7&-1&-1\\6&-4&-3\\-10&10&-7\end{array}\right]](https://tex.z-dn.net/?f=B%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D7%26-1%26-1%5C%5C6%26-4%26-3%5C%5C-10%2610%26-7%5Cend%7Barray%7D%5Cright%5D)
Required
2A - 4B
To solve 2A - 4B, we first multiply matrix A by 2 and matrix B by 4
So, if
![A = \left[\begin{array}{ccc}-1&9&2\\10&-10&2\\-5&6&-5\end{array}\right]](https://tex.z-dn.net/?f=A%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-1%269%262%5C%5C10%26-10%262%5C%5C-5%266%26-5%5Cend%7Barray%7D%5Cright%5D)
![2A = 2 *\left[\begin{array}{ccc}-1&9&2\\10&-10&2\\-5&6&-5\end{array}\right]](https://tex.z-dn.net/?f=2A%20%3D%202%20%2A%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-1%269%262%5C%5C10%26-10%262%5C%5C-5%266%26-5%5Cend%7Barray%7D%5Cright%5D)
![2A = \left[\begin{array}{ccc}-2&18&4\\20&-20&4\\-10&12&-10\end{array}\right]](https://tex.z-dn.net/?f=2A%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-2%2618%264%5C%5C20%26-20%264%5C%5C-10%2612%26-10%5Cend%7Barray%7D%5Cright%5D)
If
![B = \left[\begin{array}{ccc}7&-1&-1\\6&-4&-3\\-10&10&-7\end{array}\right]](https://tex.z-dn.net/?f=B%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D7%26-1%26-1%5C%5C6%26-4%26-3%5C%5C-10%2610%26-7%5Cend%7Barray%7D%5Cright%5D)
then
![4B = 4*\left[\begin{array}{ccc}7&-1&-1\\6&-4&-3\\-10&10&-7\end{array}\right]](https://tex.z-dn.net/?f=4B%20%3D%204%2A%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D7%26-1%26-1%5C%5C6%26-4%26-3%5C%5C-10%2610%26-7%5Cend%7Barray%7D%5Cright%5D)
![4B = \left[\begin{array}{ccc}28&-4&-4\\24&-16&-12\\-40&40&-28\end{array}\right]](https://tex.z-dn.net/?f=4B%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D28%26-4%26-4%5C%5C24%26-16%26-12%5C%5C-40%2640%26-28%5Cend%7Barray%7D%5Cright%5D)
So; 2A - 4B becomes
![\left[\begin{array}{ccc}-2&18&4\\20&-20&4\\-10&12&-10\end{array}\right] - \left[\begin{array}{ccc}28&-4&-4\\24&-16&-12\\-40&40&-28\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-2%2618%264%5C%5C20%26-20%264%5C%5C-10%2612%26-10%5Cend%7Barray%7D%5Cright%5D%20-%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D28%26-4%26-4%5C%5C24%26-16%26-12%5C%5C-40%2640%26-28%5Cend%7Barray%7D%5Cright%5D)
![\left[\begin{array}{ccc}-2-28&18-(-4)&4-(-4)\\20-24&-20-(-16)&4-(-12)\\-10-(-40)&12-40&-10-(-28)\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-2-28%2618-%28-4%29%264-%28-4%29%5C%5C20-24%26-20-%28-16%29%264-%28-12%29%5C%5C-10-%28-40%29%2612-40%26-10-%28-28%29%5Cend%7Barray%7D%5Cright%5D)
![\left[\begin{array}{ccc}-30&18+4&4+4\\20-24&-20+16&4+12\\-10+40&12-40&-10+28\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-30%2618%2B4%264%2B4%5C%5C20-24%26-20%2B16%264%2B12%5C%5C-10%2B40%2612-40%26-10%2B28%5Cend%7Barray%7D%5Cright%5D)
![\left[\begin{array}{ccc}-30&22&8\\-4&-4&16\\30&-28&18\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-30%2622%268%5C%5C-4%26-4%2616%5C%5C30%26-28%2618%5Cend%7Barray%7D%5Cright%5D)
Hence, 2A - 4B is equivalent to
![\left[\begin{array}{ccc}-30&22&8\\-4&-4&16\\30&-28&18\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-30%2622%268%5C%5C-4%26-4%2616%5C%5C30%26-28%2618%5Cend%7Barray%7D%5Cright%5D)
Answer: 5
Step-by-step explanation:
20/4=5 which is 20%
5*5=25 which is the number
20% of the number is
100/20=5
25/5=5
Answer:
Infinitely many solutions.
Step-by-step explanation:
2x+y=3
6x=9-3y
-------------
y=3-2x
6x=9-3(3-2x)
6x=9-9+6x
6x=6x
infinitely many solutions
<span>1. </span><span>Nia has 2, 3, 8, 9 and 5 in her
cards. How can she arrange it to be an even numbers with the 2 in the ten
thousands place.
Now, Nia has 5 cards, that means, the biggest value she can have is ten
thousands which is stated to be 2.
=> 20 000
=> We still have 3, 8, 9 and 5
=> Let’s have 3 thousands, which is
also an even number
=> let’s have 5 as hundreds, also an even number
=> We can have 9 tens, which is also an even number
=> and last is 8 ones, which is also an even number
Thus, the number will be:
=> 23 598, this is an even number because it can be divide by 2
=> 11 799
</span>
divide total miles by time:
220 / 3.5 = 62.857
rounded to nearest tenth = 62.9 miles per hour