Question

how can i find the sum of three consecutive numbers

Answer 1

You mean they are unknown, and you need to write an equation?

Answer 2

If the lowest integer is x, then the second one is (x+1) and the third one is (x+2).

The sum would be = `x + (x+1) + (x+2)` = x + x + x + 1 + 2 = `3x+3`

Answer 3

sorry i meant the sum of three consecutive even integers of -54 how do i find the answer?

Answer 4

Since they are even, then the difference between them is 2.

Use the idea that @SolomonZelman gave you, but modify it this way:
Let the smallest number be x.
Then the next larger number is x + 2
The largest of the three numbers is x + 4.

The sum then is:
x + x + 2 + x + 4

Set that sum equal to -54.

Then solve for x.
That gives you the smallest number. Then add 2 to x to find the middle number, and add 4 to x to find the largest number.

Answer 5

i dont understand, why x? and how do i get to the answer thank you

Answer 6

Let's say you have the number 2.
And I ask you what is the next even number after 2, you would say 2+2 or 4 right?
And if I asked for the third even number after 2, you would say 2+4 or 6 right?

Let's say you have the number x. (assume x is even)
The next even number after x, would be x+2.
The third even number after x, would be x+4.
The sum of these numbers would be (x)+(x+2)+(x+4)
or dropping the ( ) you could say x+x+2+x+4
and you want this to be equal to -54 as you said above...
So you have the equation x+x+2+x+4=-54 to solve.
So you will need to first combine your like terms on the left hand side.
That is do you know what x+x+x=? and you should know 2+4=6...

Answer 7

so its x+x+x+2+4= -54? where do i go from there? :D

Answer 8

on the left- hand side of your equation:

A/ add up the x's
B/ add up the numbers

Answer 9

IOW, simplify it a bit... :p

Answer 10

In math (Algebra) we use letters (called variables) to represent unknown amounts.
Since we don't know what the three even numbers are, we use the letter x, here called a variable, to represent the smallest of the three unknown even numbers.
Once we choose x to represent the smallest of three even numbers, the other two even numbers are x + 2 and x + 4, as explained in an earlier response above.

The sum of the three numbers is -54, so we can write this as an equation:

x + x + 2 + x + 4 = -54

We now combine all x's on the left side.

x is the same as 1x

1x + 1x + 2 + 1x + 4 = -54

1x + 1x + 1x + 2 + 4 = -54

Adding 1x + 1x + 1x, we get 3x;
also, 2 + 4 = 6, so we now have

3x + 6 = -54

Now we need to subtract 6 from both sides of the equation.

3x + 6 = -54
- 6 -6
--------------
3x = -60

Now we divide both sides by 3 to get:

3x/3 = -60/3

x = -20

Since x represents the smallest of the three numbers,
now we know that the smallest of the 3 consecutive even numbers is -20.
The next number is x + 2 = -20 + 2 = -18
The largest of the 3 number is x + 4 = -20 + 4 = -16

The numbers are -20, -18, -16

Now let's check.
-20, -18, and -16 are consecutive even numbers.
What is -20 + (-18) + (-16) = ?
-20 + (-18) + (-16) = -54
The sum of the three numbers is -54, so our answer is correct.

The three numbers are -20, -18, and -16.