Answer:
This sum is the sum of an arithmetic sequence. There is a formula for the sum of an arithmetic sequence which can be looked up or derived by a variety of means.
A nice approach for this sequence is the following. Notice that the sum of first and last number in the sequence is the same as the sum of the second and second last, and also the same as the sum of the third and third last, and so on.
There are n of these pairs. So the desired sum is n x (first number + last number). But the first number is 1 and the last on is 2n. Thus the desired sum is n(1 + 2n).
Hope this helps!!
Mark Brainleast!!!!!!!!!!!
Answer:
$2x
Step-by-step explanation:
- x × 2 = 2x
I hope this helps!
This is a good question... but is there multiple choice, i want to know if my answer matches
Answer:
3x - 5 = 10
Step-by-step explanation:
9 represents the event, 13 represents all possible events.
I have a bag of 13 marbles. 9 of my marbles are blue, 4 are red. My probability of reaching in and pulling out a blue marble at random is 9/13 (Which is 69%)
