Slope: find k so kx-3y=7 has m=2; so (2k,3), (1,k) has m=2

L

lovezoey101

New member
Joined
Aug 20, 2008
Messages
16
Could someone please do these 2 to help me understand my homework?
find the value of k so that the given line has slope m.
kx-3y=7,m=2

find the value of k so that the line through the given points has slope m.
(2k,3), (1,k);m=2
thank you.
 
Re: Slope

lovezoey101 said:
Could someone please do these 2 to help me understand my homework?
find the value of k so that the given line has slope m.
kx-3y=7,<<<< Write it in y = mx + b form
m=2

find the value of k so that the line through the given points has slope m.
(2k,3), (1,k);

slope of a line through two points (x[sub:9jqc4npg]1[/sub:9jqc4npg],y[sub:9jqc4npg]1[/sub:9jqc4npg]) and (x[sub:9jqc4npg]2[/sub:9jqc4npg],y[sub:9jqc4npg]2[/sub:9jqc4npg])

would be

\(\displaystyle slope \, = \frac {y_2 \, - \, y_1}{x_2 \, - \, x_1}\)

Please show your work/thoughts - so that we know where to begin to help you.

m=k+1
thank you.
Click to expand...
 
Re: Slope

thanks but i dont understand how to write these in in y=mx+b
i was never taught it
could you please do one of these?
 
Re: Slope

I'll do a similar problem for you:

find the value of A so that the given line has slope m.

Ax + By = C, m = M

By = -Ax + C

y = -(A/B)x + (C/B) <<< Mistakes corrected - thanks Denis

so the slope of the given line is (-A/B) - which also M according to the given in the problem.

So

-A/B = M

A = -B * M
 
Re: Slope

there arent any problems like these as examples in my book
and the site, i understand slope in general
just not these
 
lovezoey101 said:
there arent any problems like these as examples in my book and the site, i understand slope in general just not these
Click to expand...
It is unfortunate that neither your book nor your instructor covered this material. Since it is not reasonably feasible to attempt here to replace the missing hours of classroom instruction, you will need to do some self-study.

The second exercise you posted asks only that you plug the given values into the "slope" formula, "cross-multiply", and solve the resulting linear equation for the value of "k". Since you say that you understand slope completely, you must be having difficulty with solving linear equations.

. . . . .Google results for "solving linear equations"

For the first exercise, you need to plug the given value into the given equation, and find the slope. This can be done by solving for "y = mx + b", where "m" (as you know) is the value of the slope. So I will guess that, for this exercise, you have having difficulty with solving the equation for "y=", with the concept of the equation of a straight line, or with plugging x-values into line equations and solving for the y-values (as is done for graphing). Any of these topics would suffice to find the answer to this exercise.

. . . . .Google results for "solving for y=mx+b"

. . . . .Google results for "line equations"

. . . . .Google results for "graphing linear equations"

Please read at least two lessons at each link. Once you have learned the basic terms and techniques, please review the advice and suggestions you have received here, and attempt the exercises. If you get stuck, you will then be able to reply with a clear listing of your work and reasoning so far.

Thank you! :D

Eliz.
 
Re: Slope

lovezoey101 said:
thanks, but i really dont understand it
Click to expand...

Hi Zoey:

Are you able to solve the first equation for Y?

As Subhotosh instructed, that is the very first step.

If you are not able to solve the first equation for Y, then can you tell us why?

If you are able to tell us why you're stuck, then we will know how to help you.

~ Mark :)
 
Re: Slope

Subhotosh Khan said:
By = -Ax + C
y = -(B/A)x + (C/A)
Click to expand...
In case you're confused Zoey, Mr Khan meant:
y = -(A/B)x + (C/B)

So the slope (or the m in the equation) is -A/B
 
Re: Slope

eeYikes....

That was a very intelligent mistake - thought about it - reviewed it - and did not catch it.

Fixed it above - thanks Denis..
 
You must log in or register to reply here.
Top