It is 780.99999 sorry if i'm incorrect
The unit rate is $1.97 per lightbulb. Multiply $1.97 by 7 to get 13.79
Answer:

Step-by-step explanation:
To find the average rate of change of a function over a given interval, basically you need to find the slope. The mathematical definition of the slope is very similar to the one we use every day. In mathematics, the slope is the relationship between the vertical and horizontal changes between two points on a surface or a line. In this sense, the slope can be found using the following expression:

So, the average rate of change of:

Over the interval 
Is:


Therefore, the average rate of change of this function over that interval is 3.
Ok well...
1200 times .25 is 300 so subtract 1200-300= 900 is the decreased number :)
Hope it helps! :)
Multply both sides of the equation by 7.

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When the variable is in the numerator of a proportion like this, you can solve it by multiplying by that denominator. That multiplication cancels the denominator and gives you the value of the variable.
In general, you multiply by the reciprocal of the coefficient of x. When that coefficient is 1/7, you multiply by 7/1. Of course, you know that 7/7 = 1 and that x/1 = x.