Answer:
b + g = 25
b = g + 3
Explanation:
Let b = number of boys.
Let g = number of girls.
"Mrs. Smith has a total of 25 kids in her class."
b + g = 25
"There are 3 more boys than there are girls."
b = g + 3
The system of equations is:
b + g = 25
b = g + 3