The sequence 15, 21, 27, 33, 39, , 75 has 11 terms. Evaluate the related series. a.) 0420
b.) 495
c.) 0210
d.) 480

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

Since the result of the above expression gives 6, then it is an arithmetic series;

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

x = 16

Step-by-step explanation:

2x + (3x-6)  = 74

5x -6 = 74

5x = 74 + 6

5x = 80

x = 16