Find the sum of 12th term of the following AP series 7,11 and 15.

Mathematics

2 answers:

Ahat [919]2 years ago

7 0

Answer:the sum of the 12th term of the AP is 348

Step-by-step explanation:

7,11,15

Common difference=d=11-7

d=4

First term=7

Using the formula

Sn=n/2 x (2a+d x (n-1))

S12=12/2 x (2x7+4x(12-1))

S12=6 x (14+4x11)

S12=6 x (14+44)

S12=6 x 58

S12=348

Alexandra [31]2 years ago

4 0

It is adding 4 each time.

Just calculate the first 12 terms and add them up.

Term 1 = 7 + 4*0 = 7
Term 2 = 7 + 4*1 = 11
Term 3 = 7 + 4*2 = 15
Term 4 = 7 + 4*3 = 19
Term 5 = 7 + 4*4 = 23
Term 6 = 7 + 4*5 = 27
Term 7 = 7 + 4*6 = 31
Term 8 = 7 + 4*7 = 35
Term 9 = 7 + 4*8 = 39
Term 10 = 7 + 4*9 = 43
Term 11 = 7 + 4*10 = 47
Term 12 = 7 + 4*11 = 51

Sum of first 12 terms = 348

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AVprozaik [17]

Answer: 22.5 degrees

Step-by-Step Explanation:

As we can see, we are given a line, which is a straight angle. Hence, it will be of 180 degrees.

=> All the angles sum up to 180.

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Therefore, x = 22.5 degrees

Verification:

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6 0

2 years ago

An item originally costs $16.95 and is on sale for 22% off the original price. The sales tax is 6.5%. Find the cost of the item

olga_2 [115]

Answer:

$14.08

Step-by-step explanation:

$16.95 * 22% = $3.729

$16.95 - $3.729 = $13.221

^ to find the sale price of the item

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