+0  
 
0
31
2
avatar+476 

What is the ordered pair of integers $(x,y)$ for which $12x + 21y = 15$ and $21x + 12y = 51$?

gueesstt  Apr 12, 2018
Sort: 

2+0 Answers

 #1
avatar+560 
+2

This is a system of equations problem.  

 

To easiest way to solve this is first add both equations. 

 

12x + 21y + 21x + 12y = 51 + 15

 

So 33 y + 33x = 66 

 

x + y = 2 

 

We can use x = 2 - y and plug this in to equation #1.

 

12 ( 2 - y ) + 21y = 15 

 

24 - 12y + 21y = 15

 

y = -1 

x = 3 

 

The ordered pair you are looking for is (3, -1)

supermanaccz  Apr 12, 2018
 #2
avatar+476 
+1

Thank you!

gueesstt  Apr 12, 2018

32 Online Users

avatar
avatar
We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details