How do i do this fraction problem?

[ToDieIsGain]

I don't know how to get the answer for (5/6, 2/3) (1/6, 1/3) using function notation, m=y2-y1/x2-x1. So i need the slope. This is an example problem, i know m=1/2, but i dont know how to work it out to that point???

 

[HallsofIvy]

I don't know how to get the answer for (5/6, 2/3) (1/6, 1/3) using function notation, m=y2-y1/x2-x1. So i need the slope. This is an example problem, i know m=1/2, but i dont know how to work it out to that point???

Do you know that in an xy-coordinate system, a point is always given as (x y)? So that $\displaystyle x_1= 5/6$ and $\displaystyle y_1= 2/3$? And that $\displaystyle x_2= 1/6$ and $\displaystyle y_2= 1/3$?

Putting those into your formula gives $\displaystyle \frac{y_2- y_1}{x_2- x_1}= \frac{1/3- 2/3}{1/6- 5/6}$.

If you can get that far, can you find 1/3- 2/3? What about 1/6- 5/6? For the latter, remember that you can write $\displaystyle 1/6- 1/3= 1/6- 2/6$. What is that equal to.

And, finally, you divide fractions by "inverting" the denominator and multiplying: $\displaystyle \frac{a/b}{c/d}= \frac{a}{b}\frac{d}{c}$.

Now, you say you "don't know how to get the answer". The answer to what question? You never do say that.

 

[DrPhil]

I don't know how to get the answer for (5/6, 2/3) (1/6, 1/3) using function notation, m=y2-y1/x2-x1. So i need the slope. This is an example problem, i know m=1/2, but i dont know how to work it out to that point???

We need to see your work to know where you are getting stuck!

The first step is to plug in the values in the equation for the slope:

$\displaystyle \displaystyle m = \dfrac{y_2 - y_1}{x_2 - x_1} = \dfrac{\frac{1}{3} - \frac{2}{3}}{\frac{1}{6} - \frac{5}{6}}$

Is that what was giving you trouble?

 

[ToDieIsGain]

I get how to put in y2 y1/x2 x1. I dont get how to do the math with the fractions after. so then i do 1/3-2/3, and get 1/3. Then i do 1/6-5/6 and get 4/6. then its 1/3 over 4/6. at this point i become stuck.

i tried to invert and then multiply, but didnt come out to m=1/2. thats the answer im given in the ex.

 

[ToDieIsGain]

all im trying to solve is for m right now.

 

[DrPhil]

I get how to put in y2-y1/x2-x1. I dont get how to do the math with the fractions after. so then i do 1/3-2/3, and get 1/3. Then i do 1/6-5/6 and get 4/6. then its 1/3 over 4/6. at this point i become stuck.

i tried to invert and then multiply, but didnt come out to m=1/2. thats the answer im given in the ex.

Right idea, but some flaws in execution. The numerator is (1/3)-(2/3), but that subtraction is not (1/3):
(1 - 2)/3 = ..

Likewise in the denominator, subtracting 5 from 1 does not equal 4:
(1 - 5)/6 = .. [Note: 4/6 reduces to 2/3]

The "invert and multiply" rule should work - even though your values for the numerator and denominator both had errors, those two errors cancel out and you should have gotten the correct answer.
(1/3)÷(4/6) = (1/3)×(6/4) = . . .

 

[Deleted member 4993]

I get how to put in y2 y1/x2 x1. I dont get how to do the math with the fractions after. so then i do 1/3-2/3, and get 1/3. Then i do 1/6-5/6 and get 4/6. then its 1/3 over 4/6. at this point i become stuck.

i tried to invert and then multiply, but didnt come out to m=1/2. thats the answer im given in the ex.

1/3 - 2/3 = - 1/3

1/6 - 5/6 = - 4/6 = - 2/3

(-1/3) ÷ (-2/3) = (-1)X(1/3) ÷ [(-1)X(2/3)] = (1/3) ÷ (2/3) = (1/3) x (3/2) = (1/2)

You need to review your middle-school arithmetic.

 

[ToDieIsGain]

Middle school arithmetic, thats what it is, thank you!!

I see now, ok i was inverting both the bottom and top fractions, so i was getting 18/4, now i get 1/2. Thank you! Dr. Phil.