- Thread starter rjohnson
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rjohnson said:Solve this equation by the substitution method and determine whether the equations are dependent, independent or inconsistent.

3x-6y=5

2y-4x-6 this is not an equation, please check it.

please show what you have tried to solve this system.

also, just fyi ... I would not use substitution to solve this system.

3x-6y=5

2y=4x-6

6y=3x+5

3x-6y=5

3x-6y+6y=5+6y

3x=5+6y

x=5/3+6y

x=1.66+6y

2y=4(1.66+6y)-6

2y=6.66+24y-6

2y=.66+24y

y=.66/2+24y

y=.333+24y

y=1/3+24y

You said that it was not an equation. does that not make it inconsistent seeing that it cannot be solved?

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2y=4x-6

now that I see what the second equation is, let's do a substitution ...

first off ...

2y = 4x - 6

divide all terms by 2 ...

y = 2x - 3

now, substitute (2x - 3) for y in the first equation ...

3x - 6(2x - 3) = 5

distribute the -6 ...

3x - 12x + 18 = 5

combine like terms ...

-9x = -13

x = 13/9

go back to y = 2x - 3, substitute 13/9 for x and determine the value of y ...

y = 2(13/9) - 3 = 26/9 - 27/9 = -1/9

Practice. You just gotta to play around w/it and w/expirience you will learn what methods are better.rjohnson said:Thank you for the help. You make it seem so easy. How do you do it? I cannot seem to get a grasp of algebra.