The sum of three consecutive even numbers is 552. What is the 1st number?

Let 2n = the first of three consecutive even numbers, where n is an integer.

Let 2n + 2 = the second of three consecutive even numbers, and

Let 2n + 4 = the third of three consecutive even numbers.

We're given that "sum of three consecutive even numbers is 552." We can translate this English sentence mathematically into the following equation to be solved for n:

2n + (2n + 2) + (2n + 4) = 552

Removing the parentheses, we have:

2n + 2n + 2 + 2n + 4 = 552

Now, by the Commutative Law of Addition, i.e., a + b = b + a, we have on the left side of the equation:

2n + 2n + 2n + 2 + 4 = 552

Now, collecting like-terms on the left, we get:

6n + 6 = 552

To solve for the variable n, We now begin isolating n on the left side by subtracting 6 from both sides as follows:

6n + 6 - 6 = 552 - 6

6n + 0 = 546

6n = 546

Now, divide both sides by 6 to finally solve for n:

(6n)/6 = 546/6

(6/6)n = 546/6

(1)n = 91

n = 91

Therefore, the first of three consecutive even numbers, 2n, is:

2n = 2(91)

= 182

The second of three consecutive even numbers is:

2n + 2 = 2(91) + 2

= 182 + 2

= 184

The third of three consecutive even numbers is:

2n + 4 = 2(91) + 4

= 182 + 4

= 186

CHECK:

2n + (2n + 2) + (2n + 4) = 552

182 + 184 + 186 = 552

552 = 552

Therefore, the desired and first of three consecutive even numbers is indeed 2n = 182.