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2 years ago

In an arithmetic sequence, a3=15 and a8=0. What is the value of a5?

Mathematics

1 answer:

Nina [5.8K]2 years ago

7 0

Answer:

a3=15 , n=3

a8=0, n=8

a5 = ?

an = a1+ (n-1)d

a3 = a1 + (3-1) d

a3=a1+2d

and a8 = a1 + (8-1 )d

a8= a1+ 7d

15 = a1 + 2 d-------1

0= a1 +7 d----------2

substacting eq 2 from eq 1

15= - 5d

- 5d = 15

divide by - 5

d = -3

putting the value of d in eq 1

15 = a1 + 7 (-3)

15 = a1 -21

adding 21 on both sides

a1-21+21= 15+21

a1 = 36

a5 = ?, n=5, d= -3, a1=36

a5 = 36 + (5-1) (-3)

= 36+(4)(-3)

= 36-12

= 24

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Help please! 10 points!

IgorC [24]

Answer:

21.6 or 22

Step-by-step explanation:

Triangles have same angles. This means that they are proportion.

50/27 = 40/x

when you cross multiply to solve x, 50x = 1080

so x = 21.6

If you have to nearest whole number, it will be 22

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2 years ago

Find the minimum value of c = 4x + 3y

shutvik [7]

Step-by-step explanation:

C=4x+3y Constraints: x is greater than or equal to 0 2x + 3y is greater than or equal to 6 3x - 2y is less than or equal to 9 x + 5y is less than or equal to 20

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2 years ago

The sign of the product of –35 and –625 is

Anarel [89]

Step-by-step explanation:

The mathematical sign for the operation is subtraction.

To Solve This You Will Need To;

1] The sign of the product of -35 and -625 is;

It's going to be;

-35--625

The negative sign will turn into addition sign before you can operate it. So it's going to be;

-35+625=590(positive)

It's just like subtracting 35 from 625.

2] The sign of the product of 263 and 0 is;

263-0

With this no quantity is going to be subtracted so the 263 will remain the same. 

So 263-0=263(positive)

3] The sign of the product of -21 and 451 is;

-21-451

With this you won't subtract but rather you'll add and when you add the answer is going to be -472

-472(negative)

4] The sign of the product of -350 and 89 is;

-350-89

With this you will add it but you won't subtract the negatives so it's going to be;

-350-89=-439(negative)

Hope I am Correct I didn't really understand your question well. But Good Luck:)

3 0

2 years ago

Read 2 more answers

The hour hand on a clock is 4 cm long, and the minute hand is 10 cm long. What is the exact distance between the tips of the han

Allushta [10]

Answer:

2 sqrt(19)

Step-by-step explanation:

We know that the angle between the two hands

360 /12 *2 = 60 degrees

We divide by 12 because there are 12 number and multiply by 2 because there are 2 number between 10 and 12

This is a triangle where we know 2 sides and the angle between them.

We can use the law of cosines to determine the third side

c^2 = a^2 + b^2 -2abcosC

Where C is the angle between sides a and b

a =4 and b = 10 C = 60 and we are looking for side c

c^2 = 4^2 + 10^2 -2*4*10 cos60

c^2 =16+100 - 80cos 60

c^2 = 76

Take the square root of each side

sqrt(c^2) = sqrt(76)

c = sqrt(76)

c =sqrt(4) sqrt(19)

c =2 sqrt(19)

4 0

2 years ago

22.a) A fruit vendor bought 1948 oranges on a Thursday and sold 750 of them on the same day.

iVinArrow [24]

Answer: Ksh 6144

Step-by-step explanation:

On Thursday, a fruit vendor bought 1948 oranges on a Thursday and sold 750. The number of oranges left will be: = 1948 - 750 = 1198

On n Friday, he sold 240 more oranges than on Thursday. This means the number of oranges sold is: = 240 + 750 = 990.

The number for f oranges left will then be: = 1198 - 990 = 208

On Saturday, he bought 560 more

oranges, the total oranges that the vendor has now will be:

= 208 + 560 = 768

Since sold all the oranges he had at a price of Ksh. 8 each, the amount if money made will be:

= Ksh 8 × 768

= Ksh 6144

The vendor made Ksh 6144

7 0

1 year ago