1. hali12

2. mathteacher1729

What is the slope of the line?

3. hali12

idk?

4. hali12

4, 1 & 1/2

5. mathteacher1729

Not quite.. I'm not sure how you are getting those numbers.

6. hali12

idk how to do this math :/

7. ZakaullahUET

|dw:1350139808849:dw| y=mx+b is the slope intercept form put values in it

8. mathteacher1729

Slope-intercept is basically a very short way of describing ANY straight line. It can be super useful in figuring out, say, how much money you make if you get paid an hourly wage.

9. mathteacher1729

The slope is "rise over run" or the ratio (fraction) of how far up or down the line goes for every bit it moves left or right.

10. mathteacher1729

In this case, for every "rise" of negative 3 (going down three) the line goes one to the right.

11. hali12

so -3, 1?

12. mathteacher1729

So slope = -3/1. Slope = -3 (because any number divided by 1 is itself).

13. hali12

well -3 / 1

14. mathteacher1729

Yup, that's the slope.

15. hali12

thanks.. (:

16. mathteacher1729

Now the INTERCEPT just means "what value of y does this line cross the y-axis" the intercept is literally JUST A NUMBER. :)

17. hali12

4

18. mathteacher1729

So look at your picture. What value of y does the line cross (or touch, or intercept, they all mean the same thing) the y-axis?

19. mathteacher1729

Yup! :D

20. hali12

yay!

21. mathteacher1729

The slope intercept form of a line is y = mx + b where m is the slope (-3) and b is the intercept (4). Literally re-write that but instead of m write -3 and instead of b write +4 and you're done. :)

22. hali12

so, 4=-3x +4?

23. hali12

or y=-3x+4?

24. mathteacher1729

The second one.===> y=-3x+4 The crazy thing is... that describes the ENTIRE line. All the points on the line obey that equation. Question -- what is the value of Y on the line when X = 2? (look at your picture)

25. hali12

uh...

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