SOLUTION: 8.3 # 20 Solve by substitution Mcgraw Hill 6th editon, Thank you for your time!! 8x-4y=16 y=2x -4

Algebra ->  Coordinate Systems and Linear Equations -> SOLUTION: 8.3 # 20 Solve by substitution Mcgraw Hill 6th editon, Thank you for your time!! 8x-4y=16 y=2x -4      Log On


   

Question 56518: 8.3 # 20
Solve by substitution
Mcgraw Hill 6th editon,
Thank you for your time!!
8x-4y=16
y=2x -4
Answer by funmath(2933) About Me  (Show Source):
You can put this solution on YOUR website!
8.3 # 20
Solve by substitution
Mcgraw Hill 6th editon,
L1) 8x-4y=16
L2) y=2x -4
Substitute 2x-4 in for the y in L1):
8x-4%2Ahighlight%282x-4%29=16
8x-4%282x%29-4%28-4%29=16
8x-8x%2B16=16
16=16
The x's were eliminated and 16 does = 16, therefore there is an infinite number of solutions, because no matter what we put in for x, both equations will yield the same y's. We call these equations dependent. Graphically, they are the same line.
Some books let you say infinite solutions, others say the solution is (x,2x-4).
Happy Calculating!!!