Answer:

Step-by-step explanation:
• 
Let's use FOIL (first, outer, inner, last) to solve this. We'll multiply the terms by one another in that fashion.

Rearrange in decreasing exponents.

The answer is <span>C.) 2
The general form of formula is
y = a </span><span>• r^x
y - the total number of bacteria after x period of time
a - the initial number of bacteria
r - growth rate
x - period of time
Let's compare:
</span>y = a • r^x
<span>y = 280 • 2^x
Since r = 2, the growth rate is C.) 2</span>
Answer:
E. 18 children are buying their lunches
F. Rock must pay $50 each month
Step-by-step explanation:
E.
To find a percentage you multiply the number by the percentage;
60 x 70%(0.70) = 42 children brought their lunches
But we need the amount <u>buying</u> their lunches so we would subtract 60 by 42;
60 - 42 = 18 buying their lunches
F.
Again, to find the percentage we multiply it by the original;
$800 x $25(0.25) = $200 Rock paid for the down payment on the sofa
Now we need to find how much Rock still needs to pay for the sofa;
$800 - $200 = $600 more needed to pay for the sofa
Lastly, we must find how much Rock will need to pay <u>each month</u> to pay the rest of the $600. There are 12 months in a year, so we divide that by the amount left;
$600 / 12 = $50 needs to be paid each month for a year