High School

Select the correct answer.

The sum of two consecutive numbers is 157. This equation, where [tex]n[/tex] is the first number, represents the situation: [tex]2n + 1 = 157[/tex].

What is the first number?

A. 77
B. 78
C. 79
D. 80

Answer :

To solve this problem, we need to determine the first of two consecutive numbers whose sum is 157. We are given that the equation representing this situation, where [tex]\( n \)[/tex] is the first number, is [tex]\( 2n + 1 = 157 \)[/tex].

Here’s how we can solve it step-by-step:

1. Start with the given equation:
[tex]\[
2n + 1 = 157
\][/tex]

2. Subtract 1 from both sides to isolate the term with [tex]\( n \)[/tex]:
[tex]\[
2n + 1 - 1 = 157 - 1
\][/tex]

This simplifies to:
[tex]\[
2n = 156
\][/tex]

3. Divide both sides by 2 to solve for [tex]\( n \)[/tex]:
[tex]\[
n = \frac{156}{2}
\][/tex]

This calculation results in:
[tex]\[
n = 78
\][/tex]

Therefore, the first number is 78.

So, the correct answer is:
B. 78