Point Slope: m = -3/4 (-3, -7) 3x + 4y = -37

[andyboyd]

Our school does not give the class books and we are having a lot of trouble with the following this is how we are doing this and the teacher said this is wrong please help

m=-3/4 (-3 ,-7)

y+7
----- = - 3/4
x+3

4(y+7)= -3x(x+3)
4y+28= -3x -9
3x+4y= -37

Is there another way to do this if so how and how can it have a different answer

Andy

 

[stapel]

Our school does not give the class books and we are having a lot of trouble...

I'm sorry to hear that! :shock:

m=-3/4 (-3 ,-7)

Would it be correct to guess that the instructions were something along the lines of "find the equation of the line with the following slope and passing through the given point"?

(y+7)/(x+3) = -3/4
4(y+7)= -3x(x+3)

Where did the extra "x" come from...?

4y+28= -3x -9
3x+4y= -37
...the teacher said this is wrong....

This looks good to me. Clearly, it has the correct slope:

. . . . .3x + 4y = -37
. . . . .4y = -3x - 37
. . . . .y = (-3/4)x - (37/4)

...and passes through the listed point:

. . . . .3[-3] + 4[-7] ?=? -37
. . . . .-9 - 28 ?=? -37
. . . . .-37 = -37

What does your instructor say is "wrong" with it?

Is there another way to do this if so how and how can it have a different answer

Assuming the "it" you're needing to "do" is finding the line equation, there are various ways of proceeding. But the line is the line, and all of the answers, whatever the form (including your first line of work, with the fractions), would be equivalent. Please clarify what you mean by "having a different answer".

Thank you!

Eliz.

 

[Loren]

You state...

y+7
----- = - 3/4
x+3

4(y+7)= -3x(x+3) <<<It's wrong because this line should be 4(y+7) = -3(x+3).
4y+28= -3x -9
3x+4y= -37