<span> To get an explicit formula, we need to find an expression which gives the n-th term without having to compute earlier terms in the sequence. Looking at the numbers, and from the recursive formula, we see that the sequence is built by subtracting n from the previous term. This is similar to the triangular number sequence 1,3,6,10,15,... which has the explicit formula a_n = n(n+1)/2. In our case we are subtracting n from the previous term, so we multiply by -1/2 instead of 1/2. However, we also need to add a constant term to reproduce the numbers of the sequence. We can write a_1 = -1(2)/2 + c = 8. Therefore, c = 9.
So the explict formula is:
a_n = -n(n+1)/2 + 9</span>
The price of the stereo on sale
is
275 - ( 275x15% ) =
233.75
the comission is 233.75 x 2 % =
233.75 x 2/100 = 4.675
Answer:
D.120
Step-by-step explanation:
The sides AB and AC are equal and thus the angles they form with BC should be equal . Since now angle ABC is 30 then application of sum of angles in a triangle as a constant(180 degrees) we can subtract 60 degrees from it which gives 120
The answer is B, I'm on the test now.
