Answer:

Step-by-step explanation:
Given

See attachment
Required
Find AB
We have:

Make c the subject


From the attached triangle;

Hence:

Answer:

0.16
Step-by-step explanation:
According to the question the mathematical model should be

Differentiating with respect to time we get

So, the rate of change of brightness after t days is 
After 1 day means 

The rate of increase after one day is 0.16.
1/7 is bigger because a negative number is always smaller than a positive number no matter how big
Answer:
Emma will pay $5.25
Step-by-step explanation:
In order to find this, we first need to find the amount of the discount. We can do that by taking the overall amount and multiplying it by the percentage decrease.
$7.50 * 30% = $2.25
Now since we know the size of the discount, we can subtract it from the original cost.
$7.50 - $2.25 = $5.25
100 : 8 = 12.5
12.5 Km per liter is your answer