SOLUTION: I am trying to help my kid with homework, but need to understand how to do it myself. The question is solve each system by graphing and check your solution. Example:

Algebra ->  Graphs -> SOLUTION: I am trying to help my kid with homework, but need to understand how to do it myself. The question is solve each system by graphing and check your solution. Example:       Log On


   

Question 846985: I am trying to help my kid with homework, but need to understand how to do it myself. The question is solve each system by graphing and check your solution. Example: y = 2x and y = -2x + 8
Thank you!
Found 2 solutions by ewatrrr, josmiceli:
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

find two points on each line, plot them and connect with corresponding line

y = 2x     x = 0 ⇒ y = 0  +green%28P%280%2C0%29%29   x = 1 ⇒ y = 2  +green%28P%281%2C2%29%29

y = -2x + 8  x = 0 ⇒ y = 8  +red%28P%280%2C8%29%29   x = 1 ⇒ y = 6  +red%28P%281%2C6%29%29

Lines intersect at P(2,4) which is the solution  for this system of Equations

Note: 2x = -2x + 8,  4x = 8 , x = 2 (substituting for x in either EQ ⇒ y = 4)

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Here's what the plots of these 2
equations look like:
+graph%28+500%2C+500%2C+-8%2C+8%2C+-8%2C+16%2C+2x%2C+-2x+%2B+8+%29+
The way you plot each line is to pick
a value for +x+ and then find +y+
that will give you a point on the line ( x,y )
----------------
For example, say you're plotting
+y+=+-2x+%2B+8+
I'll pick +x+=+-1+
+y+=+-2%2A%28-1%29+%2B+8+
+y+=+2+%2B+8+
+y+=+10+
so, you have the point ( -1, 10 ) on the line
------------------
Just keep doing this with small whole numbers
for each of the lines, and you should end up
with 2 lines that look like my plots
Hope this helps