+0  
 
+10
3545
1
avatar+472 

Find the x- and y-intercept of the line.

1. –3x + 9y = 18

2. 7x – y = 14

3. –9x + 2y = 72

4. –7x – 2y = 56

 

 

Graph the equation.

5. y = –3

6. x = –4

7. y = –4

8. x = 1

 

Graph the equation using x and y-intercepts.

9. 8x + 4y = 32

10. –6x + 5y = –30

11. –4x – 5y = 20

12. 6x + 8y = 48

13. 3x + 7y = 21

14. 6x – 7y = –42

15. –3x + 3y = –9

16. 7x – 2y = –14

 Sep 15, 2015

Best Answer 

 #1
avatar+128090 
+10

For the first group, let x = 0 and solve for y....this will be the y intercept

Then ....let y be 0 and solve for x......this will be the x intercept

 

Here's the first one

 

1. –3x + 9y = 18

 

-3(0)  + 9y = 18

0 + 9y = 18

9y = 18   divide both sides by 9

y = 2   when x = 0     so we have the point (0,2)   this is the y intercept

 

-3x + 9(0) = 18

-3x + 0  = 18

-3x = 18      divide both sides by -3

x = -6      when y = 0      so we have the point (-6, 0)

 

Problems 2 - 4 are exactly the same as this

 

Also  9-16 are exactly the same....the only added thing is that you will plot the two points and draw a line through them.....that will be your graph !!!!

 

 

For  5 - 8...these are easy  !!!!

x= a    means that we draw a vertical line through the x axis at whatever "a" is

y = a means that we draw a horizontal line through the y axis at whatever "a" is

 

Here's 5 and 6 on the same graph......https://www.desmos.com/calculator/gwc5eya9wl

 

 

cool cool cool

 Sep 15, 2015
 #1
avatar+128090 
+10
Best Answer

For the first group, let x = 0 and solve for y....this will be the y intercept

Then ....let y be 0 and solve for x......this will be the x intercept

 

Here's the first one

 

1. –3x + 9y = 18

 

-3(0)  + 9y = 18

0 + 9y = 18

9y = 18   divide both sides by 9

y = 2   when x = 0     so we have the point (0,2)   this is the y intercept

 

-3x + 9(0) = 18

-3x + 0  = 18

-3x = 18      divide both sides by -3

x = -6      when y = 0      so we have the point (-6, 0)

 

Problems 2 - 4 are exactly the same as this

 

Also  9-16 are exactly the same....the only added thing is that you will plot the two points and draw a line through them.....that will be your graph !!!!

 

 

For  5 - 8...these are easy  !!!!

x= a    means that we draw a vertical line through the x axis at whatever "a" is

y = a means that we draw a horizontal line through the y axis at whatever "a" is

 

Here's 5 and 6 on the same graph......https://www.desmos.com/calculator/gwc5eya9wl

 

 

cool cool cool

CPhill Sep 15, 2015

1 Online Users

avatar