SOLUTION: Two numbers are such that if 21 is added to the first,it becomes twice the second, whereas if 4 is added to the second it becomes twice the first. What are the numbers?

Algebra ->  Expressions-with-variables -> SOLUTION: Two numbers are such that if 21 is added to the first,it becomes twice the second, whereas if 4 is added to the second it becomes twice the first. What are the numbers?       Log On


   

Question 642843: Two numbers are such that if 21 is added to the first,it becomes twice the second, whereas if 4 is added to the second it becomes twice the first. What are the numbers?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Two numbers are such that if 21 is added to the first,it becomes twice the second, whereas if 4 is added to the second it becomes twice the first. What are the numbers?
--------
Let the numbers be x and y
Equatiions:
x + 21 = 2y
y+4 = 2x
--------
Rearrange:
x - 2y = -21
2x - y = 4
-----
Modify:
2x - 4y = -42
2x - y = 4
-----------------
Subtract and solve for "y":
3y = 46
------------
y = 46/3
----
Solve for "x":
x - 2y = -21
x -2(46/3) = -21
x - 92/3 = -63/3
---
x = 29/3
===================
Cheers,
Stan H.
================