Answer :
To find the first number in the series of two consecutive numbers that add up to 157, we can set up an equation. Let's call the first number [tex]\( n \)[/tex]. The next consecutive number would be [tex]\( n + 1 \)[/tex].
The equation will be:
[tex]\[ n + (n + 1) = 157 \][/tex]
You can simplify that to:
[tex]\[ 2n + 1 = 157 \][/tex]
Now, we'll solve for [tex]\( n \)[/tex] step-by-step:
1. Subtract 1 from both sides of the equation:
[tex]\[ 2n + 1 - 1 = 157 - 1 \][/tex]
[tex]\[ 2n = 156 \][/tex]
2. Divide both sides by 2 to solve for [tex]\( n \)[/tex]:
[tex]\[ n = \frac{156}{2} \][/tex]
[tex]\[ n = 78 \][/tex]
So, the first number is 78. Therefore, the correct answer is B. 78.
The equation will be:
[tex]\[ n + (n + 1) = 157 \][/tex]
You can simplify that to:
[tex]\[ 2n + 1 = 157 \][/tex]
Now, we'll solve for [tex]\( n \)[/tex] step-by-step:
1. Subtract 1 from both sides of the equation:
[tex]\[ 2n + 1 - 1 = 157 - 1 \][/tex]
[tex]\[ 2n = 156 \][/tex]
2. Divide both sides by 2 to solve for [tex]\( n \)[/tex]:
[tex]\[ n = \frac{156}{2} \][/tex]
[tex]\[ n = 78 \][/tex]
So, the first number is 78. Therefore, the correct answer is B. 78.
