You first have to set up the two equations. Y is equal to the total number of gallons in a tank and x is equal to the number of hours the tanks are filling.
Since the two equations both equal y I can make them equal each other. I then solved for x as you see and got -4.
Once I found my x value I now needed to find my y. You only needed to chose one equation to solve for y, so I decided to do the first one. I plugged in -4 where my x value currently was and solved for y. I got 2.
If you have any questions please comment!! Hope this helps!!
Answer:
c
Step-by-step explanation:
according to PEMDAS you should always do whats inside the parentheses first, then you'll multiply the parentheses by 5
Answer:
2520 patterns
Step-by-step explanation:
In 'n' 10! ways, books can be arranged. But, there are also 5! permutation of blue books 'n1', 2! permutation of identical green books 'n2', and 3! permutation identical black books 'n3'.
Therefore, for non identical arrangements:

= 2520
Therefore, the books can be arranged on a shelf in 2520 patterns
<h3>
Answer:</h3>
(x, y) = (7, -5)
<h3>
Step-by-step explanation:</h3>
It generally works well to follow directions.
The matrix of coefficients is ...
![\left[\begin{array}{cc}2&4\\-5&3\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D2%264%5C%5C-5%263%5Cend%7Barray%7D%5Cright%5D)
Its inverse is the transpose of the cofactor matrix, divided by the determinant. That is ...
![\dfrac{1}{26}\left[\begin{array}{ccc}3&-4\\5&2\end{array}\right]](https://tex.z-dn.net/?f=%5Cdfrac%7B1%7D%7B26%7D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D3%26-4%5C%5C5%262%5Cend%7Barray%7D%5Cright%5D)
So the solution is the product of this and the vector of constants [-6, -50]. That product is ...
... x = (3·(-6) +(-4)(-50))/26 = 7
... y = (5·(-6) +2·(-50))/26 = -5
The solution using inverse matrices is ...
... (x, y) = (7, -5)