The temperature of a city changed by negative 15 degrees celsius over a five-week. the temperature change by the same amount each week write an expression to show the average change in the temperature of the city each week

The really short answer is, there are 5 weeks, and the temperature dropped a total of -15 celsius on those 5 weeks, how many times does 5 go into -15?  -15/5 or -3, so each week, evenly it dropped -3 celsius, and after 5 weeks, it added up to -15 celsius total from the first one.

so in the first week, or week 1, it dropped -3(1), on week 2 it dropped -3(2) on week "w" it dropped -3(w),  f(w) = -3w.

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