Question 865384
x+y=20 ... Start with the first equation.



y-4+y=20 ... Replace x with y-4 (since x = y-4 is the second equation).



Now we solve for y



y-4+y=20



2y-4=20



2y=20+4



2y=24



y=24/2



<font color="red">y = 12</font>



Once we know that <font color="red">y = 12</font>, we plug this into any equation that has x,y in it to solve for x. The easiest to pick on is the one where x is already isolated.



x = y-4



x = 12-4 ... replace y with 12 (since we just found that y = 12)



<font color="red">x = 8</font>



=======================================================



Final Answer: <font color="red">x = 8, y = 12</font>



The answer as an ordered pair is <font color="red">(8,12)</font>. Visually, this is where the two lines intersect.