# Math Help - Lines.

1. ## Lines.

Im trying to study for my final in about 2 days. I have this problem to see if lines are paralell,perpendicular or neither.

9x+3y=12
21x+7y=31

for 9x+3y=12 I got y=-3x+4

I dont know how to solve the other on besides having a fraction like y=-2x+31/7

Please if you can help me on that.

Thank you!

Find the domain of the function

Also g(x)= (5/x+14) The equation is 5 over "x" and 14

Graph the linear function

f(x)=( -7/9x) +6

2. ## Re: Help on Final for review Please.

For the first part, you will have to accept the fraction. You should get $y=-3x+\frac{31}{7}$

Assuming you mean $g(x)=\frac{5}{x+14}$, for which value of $x$ is there no solution for $g(x)$?

Assuming again that you're trying to graph $f(x)=\frac{-7}{9}x+6$, you'll need to deduce the $x$ and $y$ intercepts, and then you can simply connect them with a ruled line, potentially using a third point to verify.

3. ## Re: Help on Final for review Please.

That helps somewhat so the first question in parallel since both start -3x and different y intercepts.

2nd question can you show me why there is no solution? What if "x" is 6 wouldnt after simplifying it become 4 for ex.? If you can help me understand the process please.

And same with the last question if you can show me how to do that, and if possible to get whole numbers as in 1, 2, 4 , 6 instead of 2/3 or stuff like that

Thank you so much!! I apreciate it alot

4. ## Re: Help on Final for review Please.

Let $x=-14$ for the second part.

For the third, let $x=9$ for an easy point to plot. Let $x=0$ for another easy point. The $x$ intercept will be harder, but not impossible. You'll need to deal with the one fraction here.