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!!!!!!!!!!!
4x=20
4/4x=20/4
x=5
u want to isolate the variable to solve these equations
Answer: -7
Step-by-step explanation:
-3x - 5 = 16 (add 5 to 16)
-3x = 21 (divide by -3)
x = -7
Answer:
The average rate is 35 miles per hour
Step-by-step explanation:
To get from town A to town B takes 3 hours. The distance is 100 miles
To get from town B to town c takes 1 hours. The distance is 40 miles
To find the average rate , we need to find the total distance and divide by the total time
Total distance = 100 + 40 = 140 miles
Total time = 3 hrs + 1 hr = 4 hours
distance = rate * time
140 miles = rate * 4 hours
140/4 = rate
35 = rate
The average rate is 35 miles per hour
Answer:
35 degrees is the third angle's value.
