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trapecia [35]
3 years ago
9

The tempature is -3 degress.The temperature is expected to decrease 2.5 degress each hour until the temperature reaches -18 degr

ess. How many hours will it take to reach -18? A 6hours
B 7 hours
C 7.2 hours
D 8.4 hours
Mathematics
1 answer:
Andrews [41]3 years ago
6 0

We can set this problem up as an algebraic equation, which we can then solve to find our answer.


We start at -3. So we can start our equation with that:

-3


However, this doesn't represent any change in temperature, just that we start at -3. To show change, we will use the variable x, where x stands for the number of hours. Each hour accounts for a change of -2.5 in degrees, meaning that we must multiply our x by -2.5. We can now add this term into our equation:

-3 - 2.5x


We are trying to find when we will reach -18 degrees, so we will set our entire equation equal to -18 and solve:

-3 - 2.5x = -18

-2.5x = -15

x = 6


It will take us 6 hours, or choice A.

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