Jason is 11 times older than Zack. The sum of their ages is 48. How old is Zack?

Let j = Jason's age

Let z = Zack's age

j = 11z / / Jason is 11 times older than zack

j + z = 48 / / The sum of their ages in 48

j = 11z becomes j - 11z = 0

j - 11z = 0

j + z = 48

Multiply the top equation by - 1

-1 (j - 11z) = (0) - 1

-j + 11z = 0

-j + 11z = 0

j + z = 48

Add both equations to cancel the j terms.

12z = 48

Divide both sides by 12.

z = 4

Zack is 4 years old and Jason is 44 years old.