There are 26 students in an algebra class. The number of girls in the class is one less than twice the number of boys. How many boys are in the class.

g = girls in class

b = boys in class

g = 2b-1

girls + boys = 26

g+b=26

substitute g = 2b-1

2b-1 + b = 26

combine like terms

3b-1 = 26

add 1 to each side

3b - 1+1 = 26+1

3b = 27

divide each side by 3

3b/3 = 27/3

b = 9

There are 9 boys