Question

Choose the graph below that correctly represents the equation 3x + 9y = -18.

Answer 1

This is a multiple choice question, but I just need a brain freshener on how to loo for a graph that correctly represents this equation.

Answer 2

ok... so the easy way to do this question is findout where the equation cuts the x and y axes

x axis: let y = 0 so you are solving 3x = -18 ordered pair (answer, 0)

y:axis let x = 0 so you are solving 9y = -18 ordered par (0, answer)

match the intercepts to the graphs

Answer 3

3x + 9y = -18
9y= -3x -18
y= -1/3x - 2

Answer 4

Thank you @campbell_st and @Whiterabbit541

Answer 5

@Whiterabbit541 do you think you could help me check some more?

Answer 6

sure

Answer 7

Thanks.

Choose the slope-intercept equation of the line that passes through the point shown and is perpendicular to the line shown.
http://orange.flvs.net/webdav/assessment_images/educator_algebra1/pictures/v8/04/12/04_12_group21_graph1.gif
y = -three halvesx

y = three halvesx - 6

y = -two thirdsx - 5 thirds

y = two thirdsx - 13 thirds

Answer 8

I'm unable to answer this question because the link you have given leads to an error page.

Answer 9

Oh. Sorry, well let me [try] to explain the coordinate plane. The x-intercept is -5 and the y-intercept is 3. Then, there is a period on the point (2, -3)

Answer 10

AND - the slope is poitive.

Answer 11

Actuslly, now that I think of it...I think its D. It can't be A or C because those are negative. And I don't think it would be B because, Bs slope is too much. Do you think I'm right?

Answer 12

Seems right to me.

Answer 13

Thanks. Okay. These next two are just to check if I'm right. I hope I am not overloading you @Whiterabbit541

The functions f(x) and g(x) are described below.

f(x) = 3x - 7
g(x) = 3x + 8

The graph of g(x) is obtained by shifting up the graph of f(x) by _____ units.
Based on my calculations I put 15.


Gina pumps 40 cubic inches of air per second into a balloon. The function below shows the total amount of air f(t) inside the balloon after t seconds.

f(w) = 40t + 5

Which statement best describes the y-intercept of the graph of the function?

It is equal to 40 and represents the amount of air already present in the balloon before Gina starts blowing.

It is equal to 5 and represents the amount of air already present in the balloon before Gina starts blowing.

It is equal to 5 and represents the amount of air in the balloon after 1 second.

It is equal to 45 and represents the amount of air in the balloon after 1 second.

I chose B.

Answer 14

and you are right

Answer 15

Thank you so much. Sorry, but I am going to ask one more question to you.

For the function y = f(x), what is the ordered pair for the point on the graph when x = 3n - 4?

(3n - 4, f(n))

(3n - 4, f(3n - 4))

(x, f(3n))

(x, 3n - 4)

Answer 16

and what do you think is the answer?

Answer 17

Well, I have no idea. I know that when you want to change a slope-thingie equation to a function, you relace the y with the f(x).

Answer 18

you don't need to think it that way........
Any point has two coordinates x and y
it is given x = 3n-4
and y=f(x) =f(3n-4)
So point P can be plotted by P(x,y)

Answer 19

I hope you can get to the answer now

Answer 20

Now I get it, so it woyuld be B?

Answer 21

yeah right!

Answer 22

Oh thank you, everything understands now.