## Hiamsam 2 years ago Select the equations that are parallel and perpendicular to y = -3x - 1 and that pass through the point (3, 1).

1. Hiamsam

2. jazy

y = mx + b m is slope y = -3x - 1 -3 is slope Parallel lines have the same slope. Slope of Perpendicular lines is the opposite reciprocal...change to the opposite sign and find the reciprocal. ex: -2 to 1/2

3. jazy

So what is the slope of the parallel line?

4. Hiamsam

the slope is -3

5. Hiamsam

Is that right? @jazy

6. Hiamsam

Oh. okay. positive 1? Since I had to change it

7. jazy

The opposite reciprocal of -3 would be a positive 1/3. You switch signs(from - to +). 3 is the same as 3/1...and you find the reciprocal, which is 1/3. ------------------------------- Lets find the equation for the parallel line first. You have a slope of 3 and the given point is (3, 1).

8. jazy

Do you understand how the "opposite-reciprocal" thing works?

9. Hiamsam

Yes, I do know. Just was a little confused at the start

10. jazy

Ok (: So are you familiar with Point-Slope form?

11. Hiamsam

yes, fairly. Need a little help on that .

12. Hiamsam

so what's the next step?

13. Hiamsam

Yes :)

14. Hiamsam

Alrighty I don't see that for the answer though :/

15. jazy

Why'd it delete?! y - y1 = m(x - x1) m is slope x1 and y1 are the values of the point, (x, y) (3, 1) Slope is -3. y - 1 = -3(x - 3)

16. Hiamsam

Weird. yeah it deleted

17. jazy

Strange :/ Okay, so we have to change that^ into Slope-Intercept form. Distribute the -3. Solve for y. y - 1 = -3(x - 3) y - 1 = -3x + 9 Add 1 to both sides. y = -3x + 10 ^There is the equation for the parallel line.

18. Hiamsam

I see the answer now :P

19. jazy

Yea, so you don't really have to go through finding the perpendicular line. (;

20. Hiamsam

True! Can you help me on one last thing?

21. jazy

Sure!

22. Hiamsam

Vivian combined different amounts of white paint, blue paint, and green paint to make 145 milliliters (ml) of paint of a new shade. The amount of white paint was x ml. The amount of blue paint was 10 ml less than twice the amount of white paint, and the amount of green paint was half the amount of blue paint. This is represented in the equation below. x + (2x – 10) + 1/2 (2x – 10) = 145 What was the difference in the amounts of white paint and blue paint Vivian combined? 30 ml 35 ml 40 ml 45 ml

23. Hiamsam

nevermind I got it!

24. jazy

(:

25. Hiamsam

PASSED MY EXAM!