Question

Solve the following system of equations using the substitution method. x=4 -2y 4x+8y=20

Answer 1

Sub 4-2y fo x
4(4-2y)+8y=20
distribute
16-8y+8y=20
16=20
false

therefor there is no solution
if we look carefully, the lines are paralell

answer is no solution

Answer 2

Using the substitution method:

{    x = 4 - 2 y
  4 x + 8y = 20

Subsititute  x = 4 - 2 y

[ 4(4 - 2 y ) + 8y = 20 ]

Refine:

4( 4-2y ) + 8y = 20

16  - 8 y + 8 y = 20

0 =  16 - 20

-4 = 0

-4 = 0

-4 = 0 ( is false , therefore  the system of equations  has no solution )

hope this helps!