SOLUTION: How do I solve using a system of two equations in two variables? Jack is twice as old as Jill. In two years, Jack will be 4 times as old as Jill was 9 years ago. How old are the

Algebra ->  Coordinate Systems and Linear Equations -> SOLUTION: How do I solve using a system of two equations in two variables? Jack is twice as old as Jill. In two years, Jack will be 4 times as old as Jill was 9 years ago. How old are the      Log On


   

Question 141294This question is from textbook algerbra 1
: How do I solve using a system of two equations in two variables?
Jack is twice as old as Jill. In two years, Jack will be 4 times as old as Jill was 9 years ago. How old are they now? This question is from textbook algerbra 1

Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
let x=Jack and y=Jill

"Jack is twice as old as Jill" __ x=2y

"In two years, Jack will be 4 times as old as Jill was 9 years ago" __ x+2=4(y-9)

substituting __ (2y)+2=4(y-9) __ 2y+2=4y-36 __ 38=2y __ 19=y

substituting __ x=2(19) __ x=38