## oholmes Group Title (GEOMETRY, HELP PLEASE) Write the equation of the line with a slope of 3/7 passing through the point (9 -2) one year ago one year ago

1. Chlorophyll Group Title

Show me the slope form ....?

2. ParthKohli Group Title

$y - y_1 = m(x - x_1)$Here,$m = {3 \over 7} \\ y_1 = -2\\x_1 = 9$

3. oholmes Group Title

what is x?

4. oholmes Group Title

I got y=3/7x-2

5. hal_stirrup Group Title

hi

6. oholmes Group Title

hi

7. hal_stirrup Group Title

did you get it

8. CliffSedge Group Title

$y=mx+b, y=-2, x=9, m=3/7$ Solve for b.

9. ParthKohli Group Title

Leave $$x$$ and $$y$$ just like $$x$$ and $$y$$.

10. oholmes Group Title

ok

11. oholmes Group Title

I got y=3/7x-2

12. CliffSedge Group Title

$-2=\frac{3}{7}(9)+b, b=?$ And you got b=-2?

13. oholmes Group Title

9?

14. oholmes Group Title

@CliffSedge

15. CliffSedge Group Title

You can also use the equation Parth gave: $y−y_1=m(x−x_1) \rightarrow y−(-2)=\frac{3}{7}(x−(9))$

16. CliffSedge Group Title

Assuming you've studied algebra before, this should look familiar.

17. oholmes Group Title

2x-9= -3/7

18. CliffSedge Group Title

Ok, let's back way up then. The point is (9, -2) which means that at a particular point on the line, x=9, and y=-2. The slope is 3/7 which means from any point on the line, you can go up 3 units then to the right 7 units and find another point on the line.

19. CliffSedge Group Title

An equation of the line will be such that you can take the x and y coordinates from any point on the line and put them into the equation and make it a true statement. The slope is found by dividing the difference between the y coordinates of two points by the difference between the x coordinates of those two points (rise-over-run).

20. oholmes Group Title

This time is got 3x-7y=41

21. oholmes Group Title

22. oholmes Group Title

quick question, what type of triangle is RST?

23. CliffSedge Group Title

That looks better. You can test it by putting in the x and y coordinates from your point and seeing if it makes the statement true. i.e. 3(9)-7(-2)=?

24. oholmes Group Title

41

25. oholmes Group Title

Okay great! thank you

26. CliffSedge Group Title

Good, then the equation is true. For triangle RST, do you know how to measure the sides using the distance formula (i.e. the pythagorean theorem)? As a hint, notice the symmetry and how the sides RS and RT look to be the same length.

27. oholmes Group Title

is it isoscles?

28. CliffSedge Group Title

That would be a good guess. I'd probably still measure to make sure it wasn't equilateral. Can you see how long segment ST is?

29. oholmes Group Title

I cant tell

30. CliffSedge Group Title

The coordinates of points S and T are given. S is at (-4,7) and T is at (4,7). They are both at the height y=7, so it is a straight horizontal like going from x=-4 to x=4. How far is that?

31. oholmes Group Title

I got isoscles. I check

32. CliffSedge Group Title

Ok, I just want to make sure you know how to handle these questions in general in case you see a similar problem, that isn't so easy to solve.

33. CliffSedge Group Title

There are particular skills and knowledge that these questions are testing from you. It is important that you have these basic skills proficiently so that you can move on to more difficult problems.