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3 years ago

Find the sum of the first 90 terms of the sequence –4, –1, 2, 5, 8, ...

Mathematics

2 answers:

irinina [24]3 years ago

8 0

Answer:

11655

Step-by-step explanation:

VashaNatasha [74]3 years ago

4 0

Answer:

Answer: Sum of first 90 terms is Option d. 11655

Step-by-step explanation:

We have to find the sum of first 90 terms of the sequence -4,-1,2,5,8......

First we find the 90th term of the sequence

As we know the formula A(n)= A(1)+(n-1)d

Given from the sequence

A(1) = (-4)

n=90

d = 3

So A(n) = -4+(90-1)3

= (-4)+89×3

= 263

Now we know formula for the sum of any sequence is

Sum S(n) = $\frac{n}{2}(A(1)+A(n))$

Now we know n= 90

A(1) = -4

A(n) =263

Now we put the value in the formula

S(n)= $\frac{90}{2}(-4+263)$

= 45×259

= 11655

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slega [8]

0.088

Step-by-step explanation:

The total number of balls in the urn is;

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Because the pink balls are 8, then the probability of picking a pink ball from the urn is;

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4 years ago

Find ten solutions to the linear equation to the linear equation 1/2x+y=5

yuradex [85]

Answer:

(0,5), (2,4), (4,3), (6,2), (8,1), (10,0), (12,-1), (14,-2), (16,-3), (18,-4), and (20,-5)

Step-by-step explanation:

The given linear equation is :

$\frac{1}{2} x + y = 5$

$y = - \frac{1}{2} x + 5$

Any ordered pair that satisfies this equation is a solution.

When x=0,

$y = - \frac{1}{2} \times 0 + 5 = 5$

(0,5) is a solution

When x=2,

$y = - \frac{1}{2} \times 2+ 5 = 4$

(2,4) is a solution.

When x=4,

$y = - \frac{1}{2} \times 4+ 5 = 3$

(4,3) is a solution;

When x=6:

$y = - \frac{1}{2} \times 6+ 5 = 2$

(6,2).

When x=8,

$y = - \frac{1}{2} \times 8 + 5 = 1$

Another solution is (8,1)

When x=10,

$y = - \frac{1}{2} \times 10 + 5 = 0$

(5,0) is a solution

When x=12,

$y = - \frac{1}{2} \times 12+ 5 = - 1$

(12,-1) is a solution.

When x=14,

$y = - \frac{1}{2} \times 14+ 5 = - 2$

When x=16, we get:

$y = - \frac{1}{2} \times 16 + 5 = - 3$

When x=18, we get:

$y = - \frac{1}{2} \times 18+ 5 = - 4$

7 0

3 years ago

Karen received a $80 gift card for a coffee store. She used it in buying some coffee that cost $8.23 per pound. After buying the

aleksandrvk [35]

Answer:

Step-by-step explanation:

80 - 47.08 = 32.92

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4 0

3 years ago

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Find the Total Surface Area and the Volume of these shapes:

fiasKO [112]

Answer:

6156

Step-by-step explanation:

formula is TSA=2LW+2LH+2HW

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3 years ago

Given that A, O & B lie on a straight line segment, evaluate obtuse ∠AOC.

Evgesh-ka [11]

Answer:

AOC = 124°

Step-by-step explanation:

Angle on a straight line is 180°, therefore, the sum of the three angles shown is 180;

This can be written like so:

(3x + 94) + (x + 30) + (2x - 4) = 180

This equation can be solved to find x:

6x + 120 = 180

6x = 180 - 120

6x = 60

x = 10

AOC = 3(10) + 94

= 30 + 94

= 124

7 0

2 years ago

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