How do I set this up?

[Hadramout]

Solve the system using substitution:
{ ? − 8 = 3?
{? − 9 = 1/3x

I'm trying to find out what I could do to balance both equations out when adding or dividing, and end up with a whole number as an answer, maybe it's a decimal answer after all, could someone guide me through this problem please?

 

[topsquark]

Again, please post the question with any work you've been able to do. We'll be able to help you better.

Okay, so each equation has a solution for a specific pair of x, y. So let's solve the first equation for y: \(\displaystyle y = \dfrac{1}{3}x - \dfrac{8}{3}\)

Since we know this is also true for the x,y in the second equation we know that we can put that y value in:
\(\displaystyle \left ( \dfrac{1}{3}x - \dfrac{8}{3} \right ) - 9 = \dfrac{1}{3}x\)

See what you can do with this.

-Dan

 

[ksdhart2]

I'd double check and make sure you've copied the problem over correctly. As it stands, taken exactly as written, the problem has no solution (neither whole number nor decimal). However, if you forgot some very important grouping symbols and the second equation is actually:

y - 9 = 1/(3x)

Such that the whole thing would be typeset as:

\(\displaystyle \begin{cases}
x - 8 = 3y \\
y - 9 = \frac{1}{3x}
\end{cases}\)

Then there are two solutions, though they're honestly quite ugly...

 

[topsquark]

Good catch! ?

-Dan