equation through the points (8, 1) and (-2, -17)

[jehan.the.great]

write the equation of the lines that passes through the given two points:
a.(8, 1) (-2, -17)

?????????????
i'm soooooo lost

[pka]

Well the change in y is –18.
The change in x is –10.
Slope is change in y divided by change in x.

[jehan.the.great]

??
still lost

i have no clue what to do with the equation

[guntram]

(x-8)/(-10)=(y-1)/(-17)
So
-17x+136=-10y+10
10y-17x=-126

[pka]

Go to your text material.
Look up slope.
Then look up point slope form.
That will tell you how to do this problem.

The point being that we will not do it for you.
(Well maybe Soroban or guntram will?)

[guntram]

y=1.7x-12.6
slope is 1.7

[guntram]

I have a mistake
the right answer y=1.8x-13.4

[jehan.the.great]

ok
thanks soooooo much!

[lrivetz]

I have a mistake
the right answer y=1.8x-13.4

I tried solving the problem and came out with 1.8 but lost where -13.4 came from?

I used y1 -y2 / x1 - x2
1 - (-17) = 18

8 - (-2) = 10


18/10 = 1.8

How did you get -13.4 and where?

[soroban]

Hello, jehan.the.not.so.great!


Write the equation of the lines that passes through: (8, 1) (-2, -17)
You're expected to know something about lines . . . like some formulas?

Slope of line through (x_1,y_1) and (x_2,y_2):\;\;m\;=\;\frac{y_2\,-\,y_1}{x_2\,-\,x_1}

Equation of line through (x_1.y_1) with slope m:\;\;y\,-\,y_1\;=\;m)x\,-\,x_1)


We're given two points: \,P(8,1),\;Q(-2,-17)

The slope of line PQ is: \,m\;=\;\frac{-17\,-\,1}{-2\,-\,8}\;=\;\frac{-18}{-10}\;=\;\frac{9}{5}
'
The line through (8,1) with slope m\,=\,\frac{9}{5} is: \;y\,-\,1\;=\;\frac{9}{5}(x\,-\,8)

Simplify and we get: \: y \;= \;\frac{9}{5}x\,-\,\frac{67}{5}


. . . and don't use decimals in algebra!