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!!!!!!!!!!!
He needs to save $150 each of the last two months.
Answer:
x = 7
Step-by-step explanation:
The proportion is
14/6 = 21/(3x - 12) Cross Multiply
14*(3x - 12) = 6*21 Remove the brackets and combine
42x - 168 = 126 Add 168 to both sides
42x = 126 + 168
42x = 294 Divide by 42
x = 294/42
x = 7
Answer:
The answer is 9
Step-by-step explanation:
The answer is 9
Answer:
$789.75
Step-by-step explanation:
I'm just smart
