# help

#### Dominic

##### Junior Member
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
If you rearrange the equation into slope-intercept form, y=mx+b, m=slope and b=y-intercept.

Y = mx + b

y = -2x + 3

y= 1

Is that correct

#### dagr8est

##### Junior Member
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. 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
I think it's m is -2/3 and b is 4?

#### tkhunny

##### Moderator
Staff member
-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
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
Thank you for the help Matt.

#### ~Midnight.Kitten~

##### Junior Member
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
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
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.