So I got this problem I had to find the midpoint,slope and distance
for (-3,8) And (5,-2)
I got the midpoint as (1,3)
distance is sqr 165
Which is what the teacher got but as for the slope
I got he got sonething else
I got -5 for a slope
he got y=-5/4x + 17/4
and I have no idea how he got that
I just did the formula y2-y1/x2-x1

equation of a line
also I don't really know how to don't know how he did this
Y=2/5x +b
-4=2/5 (1) + b
ans. -22/5=b
I have no idea how he got the final ans.
Can u please explain it as easy as possible

Thanks

2. Originally Posted by Candy101
So I got this problem I had to find the midpoint,slope and distance
for (-3,8) And (5,-2)
I got the midpoint as (1,3)
distance is sqr 165
Which is what the teacher got but as for the slope
I got he got sonething else
I got -5 for a slope
he got y=-5/4x + 17/4
and I have no idea how he got that
I just did the formula y2-y1/x2-x1

equation of a line
also I don't really know how to don't know how he did this
Y=2/5x +b
-4=2/5 (1) + b
ans. -22/5=b
I have no idea how he got the final ans.
Can u please explain it as easy as possible

Thanks
HI

you know the slope passes these 2 points ie (-3,8) and (5,-2)

so the gradient of the slope will be

$m=\frac{-2-8}{5-(-3)}=-\frac{5}{4}$

THen to find the equation of the slope , you can use the formula

$y-y_1=m(x-x_1)$

$y-8=-\frac{5}{4}(x+3)$

Can you continue ?

3. ## slope of a line

(-3,8) , (5,-2)

I got -5 for a slope
he got y=-5/4x + 17/4
and I have no idea how he got that
I just did the formula y2-y1/x2-x1

( 8 - ( - 2 ) ) = 8 + 2 = 10
---------------
. ( -3 - 5 ) . = -8

10/-8 = -5/4 ... slope

y = -(5/4)x + b

insert the values of one of the sets of coordinates for x and y,
say ( -3,8 ) to get

8 = ((-5 *( -3 ))/4 + ( b ( the Y-intercept, the value of y when x = 0 ))

Minus * minus = +

8 = (15/4) + b //Subtract 15/4 from both sides,

b = 8 - ( 15/4 )

b = (4 * 8)/4 - 15/4 //convert 8 into quarters to give...

b = (32 - 15)/4 = 17/4

So the Equation of the line is...
y = -(5/4)x +17/4

====================================

The co-ordinates given are ( 1, -4 )

-4 = ( 2/5 )*1 + b

-4 = ( 2/5 ) + b... as before, subtract the slope from both sides

b = -4 - 2/5

b = -(4 * 5)/5 - 2/5 .......convert 4 into fifths to get...

b = -20/5 - 2/5 = ( - 20 - 2 )/5

b = -22/ 5

So the equation of the line is ...
y = (2/5)x - 22/5

4. How do u covert # to fifith And so how
i'm kinda having a hard tine convertin num.
Is there a way u can explain it to me? A easy way
oh n I will try to finish the rest mathaddict

thank u guys so much!

5. Originally Posted by Candy101
How do u covert # to fifith And so how
i'm kinda having a hard tine convertin num.
Is there a way u can explain it to me? A easy way
oh n I will try to finish the rest mathaddict

thank u guys so much!
Hi Candy101,

English doesn't seem to be your first language, so I will try to explain what jizer0 did for you in one part of his explanation.

(1) $-4=\left(\frac{2}{5}\right)(1)+b$

(2) $-4=\frac{2}{5}+b$

(3) $-4-\frac{2}{5}=b$

Now, this is where the conversion comes in.

In order to add or subtract fractions, you must have a common denominator. In this case that denominator is 5.

To convert -4 to fifths, we can perform the following exercise:

$\frac{-4}{1}=\frac{x}{5}$

$x=-20$

Therefore, $-4=\frac{-20}{5}$

Now, continue with step (4)

(4) $\frac{-20}{5}-\frac{2}{5}=b$

(5) $\frac{-22}{5}=b$