## anonymous one year ago What is the equation of a line that passes through points (0, 4) and (-4, -8)? y = 2x + 4 y = 2x - 4 y = 3x + 4 y = 3x - 4

1. Nnesha

first find the slope $\huge\rm m=\frac{ y_2-y_1 }{ x_2-x_1}$ substitute x's and y's by their value

2. Nnesha

$\large\rm (x_1 ,y_1)(x_2,y_2)=(0,4)(-4,-8)$ x's and y's

3. anonymous

y=2x-4

4. Nnesha

how did you get that ?

5. anonymous

idk how to do it

6. Nnesha

|dw:1439993754267:dw| now substitute x's and y's by their values remember first number in order represent x-coordinate so find sole fist $\huge\rm m=\frac{ y_2-y_1 }{ x_2-x_1}$ substitute x's and y's by their value

7. Nnesha

slope intercept form is $\huge\rm y=\color{reD}{m}x+b$ where m is slope and b is y-intercept first we have to find m value

8. anonymous

y=4x-4 like that

9. anonymous

+

10. Nnesha

|dw:1439994011436:dw| here now replace x's and y's by their valeus

11. Nnesha

|dw:1439994152620:dw| that's how you have to substitute variables by their numbers

12. anonymous

y|dw:1439994209239:dw|

13. Nnesha

|dw:1439994289089:dw| y_2 means 2nd y

14. Nnesha

now solve that fraction

15. anonymous

|dw:1439994310600:dw|

16. Nnesha

$\huge\rm \frac{ -8-4 }{ -4-0 } = ???$

17. anonymous

|dw:1439994506801:dw|

18. Nnesha

-8-4 = ???

19. anonymous

|dw:1439994601702:dw|

20. anonymous

|dw:1439994643265:dw|

21. Nnesha

no it's not equal to -4 pay attention!!

22. anonymous

ok

23. Nnesha

so -8-4 = ?? remember you should add them