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Dovator [93]
3 years ago
9

Find S15 for the series -1 + -3 + -5 + -7 +...

Mathematics
1 answer:
Ber [7]3 years ago
8 0
Hello :
the sum is  arithmetic secquence of common -diff is :
(-7)-(-5) =(-5)-(-3) = (-3)-(-1) =-2 = d
  the first term is : a1 = -1
<span>the formula of the sum :  S= (n/2)(a1 +an)
n is number of term       an = a1+(n-1)d</span>
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Cuanto es 100+100+0+0+0+0+0
jeka94

Answer:

es 200

Step-by-step explanation:

100+100=200

0+0+0+0+0=0

3 0
3 years ago
Given the below sequence:
kvasek [131]

Answer:

a) The next three terms are -1,-3,-5,-7,-9,-11,-13

b) This is arithmetic sequence

C) The difference of second term and first term is -2 in given sequence so the given sequence is an arithmetic sequence.

d) The 27 th term is -53

Step-by-step explanation:

a)  the given sequence is arithmetic sequence

the difference of second term and first term is -2

given sequence is -1,-3,-5,-7.....

the nth term in arithmetic sequence

t_{n} = a+(n-1)d

First term is a = -1 and difference is d = -2

finding fifth term is

t_{5} = -1 +(5-1)(-2)

t_{5} = -1-8 =-9

finding sixth term is

t_{6} = -1 +(6-1)(-2)

t_{6} = -1-10 =-11

finding seventh term is

t_{7} = -1 + (7-1)(-2)

t_{7} = -1 -12 =-13

The next three terms are  -9,-11,-13

The given sequence is -1,-3,-5,-7,-9,-11,-13

b) This is arithmetic sequence.

C) because the difference of second term and first term is -2 so the given sequence is arithmetic sequence.

d) by using nth term formula in arithmetic sequence

t_{n} = a+(n-1)d

a= -1 and d =-2

<u>find 27 t h term :-</u>

<u></u>t_{27} = -1 + (27-1)(-2) = -1-52=-53<u></u>

6 0
3 years ago
Penelope has $1,459.75 in her bank account. To pay her bills, she writes 4 checks for $200.25, $359.45, $125, and $299.35. Then
sammy [17]
1,459.75 - 200.25 - 359.45 - 125.00 - 299.35 = 475.70

475.70 + 375.00 = 850.70

Her account balance after the bills and deposit is $850.70
8 0
3 years ago
Read 2 more answers
Cos(−θ)=√3/3, sinθ&lt;0
Delicious77 [7]

Answer:

\sin\theta=-\frac{\sqrt{6}}{3}


Step-by-step explanation:

The given trigonometric equation is \cos(-\theta)=\frac{\sqrt{3} }{3}.

We can either use the Pythagorean identity or the right angle triangle  to solve for \sin\theta.

According to the Pythagorean identity,

\cos^2\theta+\sin^2\theta=1


Recall that, the cosine function is an even function, therefore

\cos(-\theta)=\cos(\theta)


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We substitute this value in to the above Pythagorean identity to get;


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\Rightarrow \frac{3}{9}+\sin^2\theta=1


\Rightarrow \sin^2\theta=1-\frac{3}{9}


\Rightarrow \sin^2\theta=\frac{6}{9}


\Rightarrow \sin\theta=\pm \sqrt{\frac{6}{9}}


\Rightarrow \sin\theta=\pm \frac{\sqrt{6}}{3}


But we were given that,

\sin\theta\:, so we choose the negative value.

\Rightarrow \sin\theta=-\frac{\sqrt{6}}{3}


The correct answer is B







7 0
3 years ago
What is 1 3/4 gallons, in quarts?
Serggg [28]

Answer:  7 Courts

Step-by-step explanation: One US gallon equals for US courts, so 1 3/4 x 4 is seven

5 0
3 years ago
Read 2 more answers
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