STEPS to solve by substitution (september 17)

Okay well todays assignment is to tell the steps on how to solve by substitution.

So i'll use an example to start of..
L1=2x+4y=8
L2=3x+y=13

(2x=4y=8)

step 1: then you take 4y and subtract it over to the other side
2x=8-4y

step 2: then you divide by 2 to get X by itself
x=(8-4y)/2

step:3 then you substitute it in to "L2"
3[(8-4y)/2]+y=13

step 4: then you multiply everything by 2.
6+16-8y+2y=26

step 5: collect the like terms now.
22-6y=26-22
-6y=4

step 6: to get y by its self, divide everything by -6
therefore, y= 4/-6 OR 2/-3

Now, you plot it in into one of the first solutions about
3(2/-3)+y=13
-2+y=13
y=13+2
y=15

THEREFORE: your plot would be [(2/-3),(15)]