anonymous one year ago What is the equation of the line, in point-slope form, that passes through the points (-3, -1) and (-6, 8)? y + 8 = -3(x - 6) y - 8 = -3(x + 6) y + 8 = 3(x - 6) y - 8 = 3(x + 6)

1. TheSmartOne

The slope of two points: $$\sf (x_1,y _1)$$ and$$\sf (x_2,y_2)$$ is: $$\sf\Large Slope=\frac{y_2-y_1}{x_2-x_1}$$

2. TheSmartOne

And why is the point-slope form?

3. anonymous

idk

4. TheSmartOne

Ok, then google "point-slope form" and tell me what it is.

5. anonymous

Point slope form is also the quickest method for finding the equation of line given two points

6. TheSmartOne

what equation does it show you that you get for point-slope form?

7. anonymous

8. TheSmartOne

Not an excuse... Read the first 2 paragraphs: http://www.purplemath.com/modules/strtlneq2.htm

9. TheSmartOne

Point slope form is: $$\sf y – y_1 = m(x – x_1)$$

10. anonymous

ok?

11. TheSmartOne

calculate the slope first...

12. anonymous

idk how

13. TheSmartOne

14. anonymous

i got 2.3 for theslope

15. TheSmartOne

How? Where is the work?

16. anonymous
17. TheSmartOne

*facepalm* You used a calculator, yet you plugged in the wrong point...

18. anonymous

my name explains me man

19. TheSmartOne

this will give you the correct slope... http://www.calculator.net/slope-calculator.html?type=1&x11=-3&y11=-1&x12=-6&y12=8&x=92&y=4

20. anonymous

now what

21. TheSmartOne

You have the slope, so now you can plug it into: $$\sf y – y_1 = m(x – x_1)$$ m=slope $$\sf (x_1,y_1)$$ is a point what is the slope again?

22. anonymous

-3

23. anonymous

can u just tell me answer

24. TheSmartOne

$$\sf (-3, -1)$$ and $$\sf (-6,8)$$ are both in the form of $$\sf (x_1,y_1)$$ substitute any point into the equation.