Answer: 10n^2 - 10
Step-by-step explanation:
(5n - 5)(2+2n) becomes (5n-5)(2n+2)
= (5n)(2n) + (5n)(2) + (-5)(2n) + (-5)(2)
= 10n^2 - 10
For this case, the first thing we must do is define variables.
We have then:
x: number of minutes
y: final temperature
We write then the equation that models the problem:

For y = 20 we have:

Clearing x:
Answer:
The temperature of the water will be 20 degree celcius after 150 minutes
Answer:
To figure out the change, we subtract the original temperature by the following after temperature.
18°F - original
-9°F - subsequent time after original
So we set up the equation;
18°F - (-9°F)
(Two negatives combine to form a positive)
18°F + 9°F
= <u>27°F</u> was the change in temperature.
Answer:
the second and last sentences.
Step-by-step explanation:
Its the most reasonable!