Answer:

Step-by-step explanation:
A proportional relationship has equation:

where k is the constant of proportionality.
Since we are looking for a proportional relationship that has a constant of proportionality equal to -10, we have k=-10.
We substitute k=-10 into the equation to get:

Therefore the correct choice is

![\left[\begin{array}{ccc}1&3&7\\1&1&1\end{array}\right]](https://tex.z-dn.net/?f=%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%263%267%5C%5C1%261%261%5Cend%7Barray%7D%5Cright%5D%20)
multiply 2nd row by -1 and add to first row
![\left[\begin{array}{ccc}0&2&6\\1&1&1\end{array}\right]](https://tex.z-dn.net/?f=%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D0%262%266%5C%5C1%261%261%5Cend%7Barray%7D%5Cright%5D%20)
divide the 1st row by 2
![\left[\begin{array}{ccc}0&1&3\\1&1&1\end{array}\right]](https://tex.z-dn.net/?f=%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D0%261%263%5C%5C1%261%261%5Cend%7Barray%7D%5Cright%5D%20)
multiply the first row by -1 and add to 2nd row
![\left[\begin{array}{ccc}0&1&3\\1&0&-2\end{array}\right]](https://tex.z-dn.net/?f=%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D0%261%263%5C%5C1%260%26-2%5Cend%7Barray%7D%5Cright%5D%20)
now we know
y+3=0
x-2=0
therefor
y=-3
x=2
10,000 + 7,891,287 = 7,901,287
Answer:
(1.2×3)500
Step-by-step explanation:
the 1.2 factor will be multiplied by the hours given then times that by the starting amount of bacteria.