Find the sum of the summation of 3 i minus 15, from i equals 2 to 7.

Step-by-step explanation:

Given :

We have to evaluate the given summation.

Consider

using, we have,

     ..............(1)

Consider,

Apply sum rule,

, we have,

Now, first consider,

Apply constant multiplication rule, we have,

Also,

Thus,

Similarly,

Substitute in (1) , we have,

Thus,

Thus,

answer: the first one

step-by-step explanation: use a calculator and divide the minutes by the dollars.