The sum of three consecutive even numbers is 78. What is the first number?

This is a common algebra problem. Let us start by establishing the numbers. By the way, here is the theory behind the math.
If we call the first number n , then the next consecutive even number is 2 away, so we will call it n + 2 , and so forth, the 3rd number n + 4
Lets form an equation! We know that given the sum of the 3 consecutive even numbers is 78, the equation is:
n + ( n + 2 ) + ( n + 4 ) = 78
Combine like terms, and we get:
3 n + 6 = 78
Subtract 6 from both sides.
3 n = 72
Divide both sides by 3, and we find our number to be:
n = 24
Hope this helped! Good luck.

Answered by Cam943 | 2024-06-10

x + ( x + 2 ) + ( x + 4 ) = 78 3 x + 6 = 78 3 x = 78 − 6 3 x = 72 x = 3 72 ​ x = 24
The first number is 24

Answered by 452 | 2024-06-10

The first of the three consecutive even numbers that sum up to 78 is 24. The numbers are 24, 26, and 28. Adding these together confirms they equal 78.
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Answered by Cam943 | 2024-10-23