I NEED HELP QUICKLY!!! What is the sum of the first 140 positive multiples of 3?

Mathematics

1 answer:

garri49 [273]3 years ago

5 0

Answer:

Step-by-step explanation:

The multiples of 3 are

3, 6, 9, 12, 15, ...........

The terms form an arithmetic sequence with common difference of 3.

The sum to n terms is

$S_{n}$ = $\frac{n}{2}$ [2a₁ + (n - 1)d ]

where a₁ is the first term and d the common difference

Here a₁ = 3 and d = 3, thus

$S_{140}$ = $\frac{140}{2}$ [ (2 × 3) + (139 × 3) ]

= 70(6 + 417) ] = 70 × 423 = 29610 → C

You might be interested in

5. How can you get the variable alone in the equation x + 37 = 94?

dlinn [17]

The answer is d.because you have to subtract from both side

4 0

2 years ago

. Tommy gives baseball cards to four of his friends. He gives Kiana 3 cards less than he gives Gary.

Licemer1 [7]

We need to write system of equations for this problem. Reading text we write 1 equation by 1.
first lets name our variables
x - Kiana cards
y - Gary cards
z - Monty cards
m - Willa cards

x = y-3 which we can write as y = x+3
z = x + 7
m = 2z
x + y + z + m = 74

I think easiest way to solve this is to express all variables in last equation and solve for x.
x + x+3 + x + 7+ 2x + 14= 74
5x = 50
x = 10
now we just calculate cards given to each friend

y = 13
z = 17
m = 34

7 0

3 years ago

For the function f(x)

WITCHER [35]

Given:

The function is

$f(x)=\dfrac{8\sqrt[3]{x}-8}{9}$