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labwork [276]
3 years ago
12

13. If 6 times the 6th term of an A.P. is equal to

Mathematics
1 answer:
romanna [79]3 years ago
7 0

Answer:

see explanation

Step-by-step explanation:

The n th term of an AP is

a_{n} = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Given

6(a₁ + 5d) = 13(a₁ + 12d) ← distribute parenthesis on both sides

6a₁ + 30d = 13a₁ + 156d ( subtract 13a₁ from both sides )

- 7a₁ + 30d = 156d ( subtract 30d from both sides )

- 7a₁ = 126d ( divide both sides by - 7 )

a₁ = - 18d

Now

a₁₉ = a₁ + 18d = - 18d + 18d = 0 ← as required

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Step-by-step explanation:

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3 years ago
A small dealership leased 21 Suburu Outbacks on 2-year leases. When the cars were returned at the end of the lease, the mileage
Liula [17]

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Step-by-step explanation:

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3 years ago
In a bag there are 10p coins, 20p coins and 50p coins
Scrat [10]

Answer:

Approximately 25p (please change to pounds by yourself I'm not European, sorry).

Ok so according to my research its 100 pence to one pound. Which will mean that 25p in pounds is £ 00.25

Step-by-step explanation:

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(Sorry I couldn't change to pounds)

And I tried to explain as much as possible, you can ask if you're confused.

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Arlecino [84]

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3 years ago
Solve the equation.
elena55 [62]

Answer:

C: x=-3 or x=4

Step-by-step explanation:

To solve the equation x^2-x-12=0 we need to factor it

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This means that when factored, the equation would be (x-4)(x+3)=0

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