Question 90785
Question:


Solve the system by graphing.
	x + 2y = 4
	x + 2y = –2

Answer:



If you are doing it in a graph paper,  what you have to do is,

Rewrite the given equations in terms of x as follows.

 x + 2y = 4

==> y = {{{ (1/2)(4-x) }}} ------------(1)


x + 2y = –2

==> y = {{{(1/2)(-2-x)}}} -----------------(2)

Now put some arbitrary values for x in the (1) and (2) and find out the corresponding y values.


For(1),  when x = 0, y = {{{ (1/2)(4-0) }}} = 2


when x = 1, y = {{{ (1/2)(4-1) }}} = {{{3/2}}} = 1.5


When x = 2, y = {{{ (1/2)(4-2) }}} = {{{2/2}}} = 1



Now plot this values on  the graph paper.


Similarly find out x and y values for the second equation and plot the graph.



Then the graphs will come like this....



{{{ graph( 600, 600, -10, 10, -10, 10, (1/2)(4-x) , (1/2)(-2-x) ) }}}





Here you can see that the lines are parallel...that means they do not have solutions.



Hope you found the explanation useful.



Regards.


Praseena.