## anonymous one year ago What is the slope of the line that passes through the points (2, 8) and (6, 12)? A. –5 B. –1 C. 1 D. 5

1. Luigi0210

Try using the slope formula: $$\Large m=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}$$

2. anonymous

i don't understand that

3. Luigi0210

$$\large (x_{1}, y_{1})$$ and $$\large (x_{2}, y_{2})$$ Match the coordinates with the formula $$\large (2, 8) ~~ (6, 12)$$

4. anonymous

OMG i don't understand what x1 y1 x2 y2 means

5. MrNood

the two point s oyu have are (x1,y1) and (x2,y2) in this case x1=2 y1=8 x2=6 y2=12 put those numbers into the formula that @Luigi0210 gave you m is the answer for the slope...

6. anonymous

wait so c?

7. MrNood

is that a guess? care to show a little of your working?

8. anonymous

(x1-x2) -------- (y1-y2) so 4/4=1. C.

9. anonymous

@MrNood Yes?

10. MrNood

good - that is correct |dw:1432832346785:dw|

11. MrNood

oooops |dw:1432832488643:dw|

12. MrNood

@ibacon BEWARE!! You have got the answer right in this case BUT you got the equation wrong You have the equation upside down (it is only correct here because it was 4/4) BE CAREFUL on other questions

13. MrNood

see @Luigi0210 first answer for the CORRECT formula

14. anonymous

What is the slope of the line that passes through the points (1, 7) and (–4, –8)? A. –3 B. Slope C. Irrational Numbers D. 3 so what is the x1 x2 y1 y2 and the equation? @Luigi0210 @MrNood

15. MrNood

you are given the 2 pairs of points you probably know they are in the order (x,y) in the brackets It doesn't matter which one you choose as 1 or 2 as long as you are consistent with the formula try it yourself the same as the last one

16. anonymous

okay. so.

17. anonymous

(y1- y2) =4 -------- (x1-x2) = -6 4 minus -6 = 10

18. anonymous

A. 1/3 B 3 C -1/3 D-3 10 is not here

19. MrNood

no sorry that is very wrong (x1,y1) = (1,7) (x2,y2) = (-4,-8) be careful with the signs when oyu do the subtraction

20. anonymous

i got it.

21. anonymous

correct me if im wrong

22. anonymous

(x1 -y1) =5 ------------ (x2 -y2) =15 5/15 = -3

23. MrNood

several errors: FIRSTS AND MOST IMPORTANT - you still hav eth eequation upside dowm it is y1-y2/x1-x2

24. MrNood

second 5/15 is not -3

25. anonymous

ik its 0.333 which is 1/3.

26. MrNood

let's start again (and look at my sketch from waaay above the vertical line is y2 - y1 so with you numbers what s y2 - y1?

27. MrNood

the horizontal line is x2-x1 so with your numbers what is x2-x1?

28. anonymous

-4 for the first y1 - y2

29. anonymous

and 6 for x1-x2

30. MrNood

no - that is not correct write out x1 = x2 = y1= x2=

31. MrNood

(x1,y1) = (1,7) (x2,y2) = (-4,-8)

32. anonymous

idek anymore

33. MrNood

Look - don't despair - this is mainly jjust about notation and numbers Go back to what we are trying ot find - the SLOPE of a straight line |dw:1432835712744:dw|

34. anonymous

its been an hour on 2 questions i give

35. MrNood

take ANY two points on the line: |dw:1432835788766:dw| Are you staying or going????

36. anonymous

i guess ill stay lol might as well

37. anonymous

what - what? if you give me numbers i will understand what x1 x2 y1 y2 is

38. MrNood

OK - now th eDEFINITION of the slope is the (change in y) ---------- (change in x) and that is shown in the drawing:|dw:1432835978112:dw| do you follow that?

39. anonymous

ohh 1- -4? ---------- 7 - -8

40. MrNood

YES those numbers are right BUT BUT BUT you GOTTA put the Y on top....

41. anonymous

7 minus -8 ---------- 1 minus -4

42. MrNood

correct and that equals???

43. anonymous

3..