All categories

2 years ago

Find the sum of the first 30 multiples of 8.

Mathematics

1 answer:

Anna11 [10]2 years ago

3 0

Step-by-step explanation:

sum of the arithmetic sequence

a1 = 8

a2 = a1 + 8 = 8+8 = 16

...

an = 8×n

the sum of the first n elements of such a series is

n/2 × (2×a1 + (n - 1)×d]

with d being the difference between 2 consecutive elements (= the added constant).

so,

s30 = 30/2 × (2×8 + 29×8) = 15×(31×8) = 3720

You might be interested in

Help me wiht this plssss

yulyashka [42]

Answer:

well you find. out how many all of them measure. and add them and then that answer multiply of the main number

Step-by-step explanation:

first add up all of the lengths and then find that answer multiply it to the main number and then you will get your anwer it's a 2 step problem

7 0

2 years ago

Q3.

umka2103 [35]

Answer:

8.48%

Step-by-step explanation:

Bill's weight decreases from 64.8 kg to 59.3 kg.

We need to find the percentage decrease in Bill's weight. It can be calculated as follows :

$\%=\dfrac{64.8 -59.3 }{64.8 }\times 100\\\\=8.48\%$

So, the required decrease in percentage is 8.48%.

3 0

3 years ago

I need help pleaseeeeeee

soldi70 [24.7K]

Answer:

For a triangle to be equiangular all its three interior angles must be equal, that is, each angle should measure 60˚.

Step-by-step explanation:

5 0

3 years ago

Whats 20% of 40?<br> (find the percentage of the whole)<br> im also giving brainliest!!!

Nataliya [291]

0.2 x 40
=8
(change the percentage to a decimal)

6 0

3 years ago

Suppose that a police officer measured the speed of cars on a highway for an hour. The average speed of the cars was 72 and the

anygoal [31]

I got 4.14 because i multiplied the deviation which is 4.6 by 0.9 and got that answer

8 0

3 years ago