Answer:
89
Step-by-step explanation:
Answer:
b. 495
Step-by-step explanation:
Given
15, 21, 27, 33, 39, ...., 75
Number of terms = 11
Required
Evaluate
To evaluate means to add up all term of the series above;
The first step is to determine if the series is arithmetic or exponential;
If its arithmetic, then the difference between successive terms must be equal;
In other words;
21 - 15 = 27 - 21 = 33 - 27 = 39 - 33 = 6
<em>Since the result of the above expression gives 6, then it is an arithmetic series;</em>
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The sum of n terms of an arithmetic series is calculated as this
Where n = 11
a = First term = 15
T_n = Last term = 75
The formula becomes
Hence, the series when evaluated is 495
Couldnt you just do the X's together and the Y's and your answer after you divide by each??