Algebra: solve x + 3y = -3, 9y = -3x - 9 by substitution

[itsmelana]

Please check this for me....

Solve the following system using substitution:

x + 3y = -3
9y = -3x - 9

------------------------

x= -3y-3
3y-3 for
9y= -3(-3y-3) - 9
9y=9y
No Solution

 

[tkhunny]

Re: Algebra

Please check this for me....


Solve the following system using substitution:
x + 3y = -3

9y = -3x - 9

------------------------
x= -3y-3
3y-3 for
9y= -3(-3y-3) - 9
9y=9y
No Solution

Your algebra is good. Your conclusion is bad.

What value for x makes y = y?

Hint: 9y = -3x - 9 ==> 3x+ 9y = -9 ==> x + 3y = -3 ==> The TWO lines really are the SAME line.