The sum of the first five terms is 11/2
<h3>How to determine the sum?</h3>
The series is given as:
1/2, -1,2,-4…
Calculate the common ratio of the series using
r = -4/2
Evaluate
r = -2
The sum is then calculated as:

This gives

Evaluate

Evaluate

Hence, the sum of the first five terms is 11/2
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Answer:
x = 8
Step-by-step explanation:
Since < A and < B are vertical angles, then it means that they have the same measure.
Given that m < A = (3x - 21)°, and m < B = (2x - 13)°:
We can set up the following equation to solve for the value of x:
m < A = m < B
(3x - 21)° = (2x - 13)°
3x - 21 = 2x - 13
Subtract 2x from both sides:
3x - 2x - 21 = 2x - 2x - 13
x - 21 = -13
Add 21 to both sides to isolate and solve for the value of x:
x - 21 + 21 = -13 + 21
x = 8
We must verify if we have the correct value for x by plugging in 8 into the equality statement:
(3x - 21)° = (2x - 13)°
[3(8) - 21]° = [2(8) - 13]°
(24 - 21)° = (16 - 13)°
3° = 3° (True statement. This means that we have the correct value for x).
Therefore, the value of x = 8.
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