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3 years ago

What is the sum of the first 20 terms of the series 3 + 14 + 25 + 25 + 36 +

Mathematics

2 answers:

Fynjy0 [20]3 years ago

6 0

Answer:

$S _{20} = 2150$

Step-by-step explanation:

$a _{1} = 3 \\ a _{2} = 14 \\ d = a _{2} - a_{1} = 14 - 3 = 11 \\ n = 20$

$S _{n} = \frac{n}{2} (2a + (n - 1)d) \\ \\ S _{20} = \frac{20}{2} (2(3) + (20 - 1) \times 11) \\ \\ S _{20} = 10 \times (6 + 19 \times 11) \\ S _{20} = 10 \times (6 + 209) \\ S _{20} = 10 \times 215 \\ S _{20} = 2150$

Luba_88 [7]3 years ago

5 0

2150 is the correct answer

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2 years ago

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Dahasolnce [82]

We need to solve for x. Let's try problem b:

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Let's solve for problem c:

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Let's try problem d:

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3 years ago

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grin007 [14]

Answer:

Step-by-step explanation:

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2 years ago

Read 2 more answers

2. US$ 1.7135

Brrunno [24]

Answer:

1577.8 US dollars are received for 1127 UK pounds.

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Step-by-step explanation:

The questions are solved by proportions, using a rule of three.

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1 UK pound = 1.4 US dollars