Thread: A Graph Problem :?

Graph the line x+y= 5 on the graph provided. Then graph the results.

x|y
5|0
0|?
?|?

Graph the line x-y=1 on the graph.

x|y
?|?
?|?
?|?

What is the point of intersection of the two lines?
What is the slope of line y=3/4x-1?
What is the y-intercept of line 2x+3y=6?

Find an equation of the line with slope -4/3 and y-intercept 3. Leave equation in slope-intercept form.

Find an equation of the line that goes thru the point (2,1) and has a slope of 4. Leave equation in point-slope form.

I know it's a lot but I really need a lot of help. Thank you in advance!

x+y= 5
change this so it becomes y = 5 -x
This way, u can choose any x value and subtitute it in to get y.
ie. x = 0
y = 5 - 0
y = 5
Point (0, 5)
Choose at least 3 other points to draw the line.


x-y=1
Do the same.
y = x -1
Choose at least 3 other points to draw the line.


What is the point of intersection of the two lines?
In the graph I made the dots red, where the lines intersects x and y axes.

What is the slope of line y=3/4x-1?
This is in the form of y = mx + c
m is the slope so slope = 3/4

What is the y-intercept of line 2x+3y=6?
Y intercept is when x = 0
Substitute this in and you get: 2*0 + 3y = 6
3y = 6
y = 2
Y-intercept = (0, 2)

Find an equation of the line with slope -4/3 and y-intercept 3. Leave equation in slope-intercept form.
I don't know if this is what they are looking for.
3 = -4/3x + c
Y - Int. x = 0
y = -4/3 + 3

Find an equation of the line that goes thru the point (2,1) and has a slope of 4. Leave equation in point-slope form.
I don't know if this is what they are looking for.
1 = 4x + c
1 = 8 + c
c = -7

Thank you so much for all your help! It is much appreciated! Can I ask you..how do I figure out how to fill out the input/output table? And i'm afraid the last two questions aren't what they are looking for but I sooo appreciate all your help! Thanks a mil!

Originally Posted by IHATECHONGAS

Can I ask you..how do I figure out how to fill out the input/output table?

x+y= 5
change this so it becomes y = 5 -x

In your table:
x|y
5|0
0|?
?|?

You have the x value. Subtitute this into
y = 5 -x

y = 5 - 5 = 0
y = 5 - 0 = 5
y = 5 - ? = (in this table, the x's are going down in 5s so the next value should be -5.)
y = 5 - (-5) = 10

Sooo..on this table it would be backwards???

Graph the line x-y=1 on the graph.

x|y
?|?
?|?
?|?

Originally Posted by r_maths

x+y= 5
x-y=1
Do the same.
y = x -1
Choose at least 3 other points to draw the line.

Make up 3 x points and substitute into equation y = x -1
For example. if you look at the line I drew for you.
When x = 0 y = -1 hence the point (0, -1)