A French class has a total of

39

students. The number of males is

13

more than the number of females. How many males and how many females are in the class?

If the number of males is x and the number of females is y,

x-13=y

x+y=39. Substituting x-13 for y, we have x+x-13=39 and by adding 13 to both sides we get 52=2x and dividing by 2 we get x=26

F=number of females

m=number of males

total is 39

m+f=39

males is 13 more than females

m=13+f

subbsitute 13+f for m

m+f=39

13+f+f=39

13+2f=39

minus 13 both sides

2f=26

divide both sides by 2

f=13

13 females

m=13+f

m=13+13

m=26

13 females and 26 males