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http://prntscr.com/mdypl5

 Jan 29, 2019
 #1
avatar+18018 
+2

2x + 3y = 15.5

x+y = 6        or    x = 6-y    Substitute THIS value of x into the first equation

 

2 (6-y) + 3y = 15.5

12-2y+3y = 15.5

y = 3.5                          Now sustitue THIS value of y in to the first OR the second equation to find x

 

x + 3.5 = 6

x = 2.5

 Jan 29, 2019
edited by Guest  Jan 29, 2019
 #3
avatar+99523 
0

Sorry, EP.....didn't see you doing this one, too !!!!

 

 

cool cool cool

CPhill  Jan 29, 2019
 #5
avatar+18018 
+1

Always good to see we got the SAME answers!    Sometimes, I do the work on paper, submit my answer and THEN sign in.....and you may not see I was working on it.....no worries !  cheeky

   I sometimes submit an answer that someone else is working on because there are multiple ways to answer them....and it is good to see them all....

~EP

ElectricPavlov  Jan 29, 2019
 #2
avatar+99523 
+1

2x + 3y = 15.5       (1) 

 x  +  y =   6     ⇒   y = 6 - x     (2)

 

Sub (2) into (1)

 

2x + 3(6  - x)  =  15.5

2x + 18 - 3x = 15.5

-1x + 18 = 15.5               subtract  18 from both sides

 

-1x = -2.5   

x = 2.5

 

And y =   6 - 2.5 =  3.5

 

So    ( x , y)  = ( 2.5, 3.5)   

 

 

cool cool cool

 Jan 29, 2019
 #4
avatar
0

Thank you both!!

 Jan 29, 2019

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