Use the graph to determine whether each system has no solution, one solution, or infinitely many solutions.

Question

3.  

 

x - y = 4

y = x - 4

 

 

7.  

 

x + y = 4  

x + y = 1 

 

Answer 1

3) Given system x-y = 4 ---> (1)

y = x-4 ---> (2)

Write the first equatiion slope intercept form.

-y = -x+4

y = x-4 ---> (3)

From (2) and (3) they are equal lines.

From the graph we can observe the given system has infineatly many solutions.

7) Given system x+y = 4 ---> (1)

x+y = 1 ---> (2)

Write the equatiions slope intercept form.

y = -x+4

y = -x+1

From the graph we can observe given lines are parallel.

So the system has nosolution.