Hi,

3x + y = 6  ⇒   y = 6 − 3x   |yes, good work

 x − 2y = 2 

x - 2(6 - 3x) = 2    | Careful...  = + 6x

 x -12 + 6x = 2 

   7x = 14

    x = 2   and y = 0   

 

Answer by Theo(13342)   (Show Source): You can put this solution on YOUR website!
 3x + y = 6

x − 2y = 2

solve for y in the first equation to get:

y = 6 − 3x

substitute for y in the second equation to get:

x − 2(6 − 3x) = 2

simplify to get:

x − 12 − 6x = 2 *********

this i where you went wrong.

the simplified equation should be equal to:

x - 12 + 6x = 2 

when you multiply -2 * -3x you get a + 6x, not a - 6x.

the rest of the processing would go like this:

x - 12 + 6x = 2

combine like terms to get:

7x - 12 = 2

add 12 to both sides to get:

7x = 14

divide both sides by 7 to get:

x = 2

first original equation is 3x + y = 6

substitute 2 for x to get 3(2) + y = 6

simplify to get 6 + y = 6

subtract 6 from both sides of the equation to get y = 0

your answer should be:

x = 2

y = 0

substitute these values into the second original equation.

second original equation is:

x − 2y = 2

substitute 2 for x and 0 for y to get:

2 - 2(0) = 2 which simplifies to 2 = 2

this confirms the values for x = 2 and y = 0 are good.

 

RELATED QUESTIONS

did I do this right if not can you tell me what I did wrong

2x + y = 5
x − 2y =  (answered by rothauserc)

I have tried to figure out how to properly graph this problem however, when I looked at... (answered by Fombitz,algebrapro18)

use the substitution method.
9x-2y=3
3x-6=4
Could someone please tell me if I did this  (answered by stanbon)

I have two questions I am not sure I solved correctly could you possibly help me and tell  (answered by bucky)

hey, can u help me with this, i got somehow missed on how to do it in class, 

Draw... (answered by subudear)

Please tell me if I did the following problem correctly:

If y varies inversely as x... (answered by malakumar_kos@yahoo.com)

I just want this answer explained to me.  The question ask me to use the rref function in  (answered by solver91311)

Please help me and show all work.

I am having a problem on how I would graph this.... (answered by stanbon)

Tutor, 

I was wondering if you could help me with this problem?  

Find the equation  (answered by stanbon)