help

Dominic

Junior Member
Joined
Jun 16, 2005
Messages
69
Determine the slope and y-intercept of the graph of 12 + 3y = -2 x.

I need help solving this problem. I hope someone can help me.
 

dagr8est

Junior Member
Joined
Nov 2, 2004
Messages
128
If you rearrange the equation into slope-intercept form, y=mx+b, m=slope and b=y-intercept.
 

Dominic

Junior Member
Joined
Jun 16, 2005
Messages
69
Y = mx + b

y = -2x + 3

y= 1

Is that correct
 

dagr8est

Junior Member
Joined
Nov 2, 2004
Messages
128
I'm not sure how you came up with that :shock:, but since it's just rearranging the equation, I will do it for you. :D

12+3y=-2x
3y=-2x-12
y=(-2/3)x-4

If you compare that to y=mx+b, which term corresponds with m and which term corresponds with b?
 

Dominic

Junior Member
Joined
Jun 16, 2005
Messages
69
I think it's m is -2/3 and b is 4?
 

tkhunny

Moderator
Staff member
Joined
Apr 12, 2005
Messages
10,383
-4 Close. Look at the form very carefully.
 
G

Guest

Guest
Dominic, do you understand how to get an equation into the form y = mx + b now?
 

Matt

Junior Member
Joined
Jul 3, 2005
Messages
183
Hi Dominic,

The equation was y=(-2/3)x-4 and now has the form y=mx+b.

Dominic said:
I think it's m is -2/3 and b is 4?
No, but like tkhunny wrote, you are close. Remember, the form y=mx+b has a + between the mx and b. You should rewrite the equation so that there is a + between the mx and b, before reading off the value of b. We have:

. . . . y = (-2/3)x - 4

which can be rewritten as:

. . . . y = (-2/3)x + (-4)

Now that we have a + between the mx and b, we can read off the value of b. So really, we actually have m = -2/3 and b = -4.
 

Dominic

Junior Member
Joined
Jun 16, 2005
Messages
69
Thank you for the help Matt.
 

~Midnight.Kitten~

Junior Member
Joined
Jun 27, 2005
Messages
87
so, would you do the parenthese first?
 
G

Guest

Guest
so, would you do the parenthese first?
Depends on what you're trying to do. In this problem, we're not evaluating anything, so we don't evaluate anything in parentheses first. If you had a value for x, and you plugged it into (-2/3)x - 4 and wanted to evaluate that, then you would evaluate what's in parentheses first.
 

~Midnight.Kitten~

Junior Member
Joined
Jun 27, 2005
Messages
87
wouldnt you use the formula x1/y1 x x2/yx for the slopne and intercept?
 
G

Guest

Guest
Do you mean x<sub>1</sub>/y<sub>1</sub> * x<sub>2</sub> / (y * x) ?

How would you use that?
 

~Midnight.Kitten~

Junior Member
Joined
Jun 27, 2005
Messages
87
alexflury said:
Do you mean x<sub>1</sub>/y<sub>1</sub> * x<sub>2</sub> / (y * x) ?

How would you use that?
to determine the slope.i guess theres different ways thats how it was done in my school.
 
G

Guest

Guest
How you get an answer depends on what information you know.

I don't know how you would use x<sub>1</sub>/y<sub>1</sub> * x<sub>2</sub> / (y * x) to get the slope.
 
Top