Ask a question

how to graph a linear equation with fractions

this is the problem:
-1/2x + 1/8y = 3/4
I know how to do this without fractions, this is what I have so far, now I'm stuck
-1/2x + 1/8y = 3/4
+1/2x              +1/2x
1/8y = 1/2x + 3/4
divide each by 1/8 - I don't know how to do this with a fraction

1 Answer by Expert Tutors

Tutors, sign in to answer this question.
Vivian L. | Microsoft Word/Excel/Outlook, essay composition, math; I LOVE TO TEACHMicrosoft Word/Excel/Outlook, essay comp...
3.0 3.0 (1 lesson ratings) (1)
Hi Trinity;
I assume this is...
(-1/2)x + (1/8)y = 3/4
Let's eliminate the fractions...
Let's note the fact that the denominators, also known as divisors, are 2, 8 and 4.  Let's multiply everything by 8...
8[(-1/2)x + (1/8)y] = 8(3/4)
If you would like this in the format of y=mx+b such that you can easily graph it, then let's move the -4x from the left side to the right where it becomes positive...
The slope of this line, change of y divided by change of x, is 4.
The y-intercept, value of y when x=0, is 6.
Does this help, or is there more to this question?


I am still confused.  my book says to subtract to move x to the other side of the equation.  then divide to get y by itself.
Let's do what your book says, almost...
(-1/2)x + (1/8)y = 3/4
Let's add, not subtract, (1/2)x to both sides of the equation...
We must add because the negative (1/2)x is already on the left side of the equation.  We need to cancel it as we proceed to isolate y...
Now we can multiply both sides by 8, not divide by 8...
I wish I could see your book.
Can you give me a page number?
Is that the correct page number?
yes, page 97, problem #15 is the one I was doing,  the book is the 8th grade florida, it is blue and white with the kid playing soccer.
I cannot find it using the hyperlink you provided.
How did the test go?