Algebra
posted by Sarah .
this december your brother jack will be 2 years from being twice as old as your sister Jen. the sum of jacks age and three times jens age is 68. how old is jen?

Jack's age=2*(Jen's age)2
[Jack's age]+3*(Jen's age)=68
use substitution method:
[2*(Jen's age)2]+3*(Jen's age)=68
Solve for Jen's age. 
how to solve a matrice when it's like b21 and it givec you to sets of matrices like AND IT SAYS TO ID EACH ELEMENT
A.)O 1 B.)6 3 1/2
1.5 3 AND
7 2 
Jen's age = X yrs.
Jack's age = (2X 2) YRS.
(2X  2) + 3X = 68,
2X + 3X 2 = 68,
5X = 68 + 2 = 70,
X = 14 yrs. = Jen's age.