SOLUTION: 8x-4y=16 y=2x-4 Solve by substition 4y=8x-16 divide both sides by 4y y=8x-16/4 y=8x/4+16/4 y=4x/2+16/4 reduce y=2x+4 Upon plugging top equation of y into bottom e

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: 8x-4y=16 y=2x-4 Solve by substition 4y=8x-16 divide both sides by 4y y=8x-16/4 y=8x/4+16/4 y=4x/2+16/4 reduce y=2x+4 Upon plugging top equation of y into bottom e      Log On


   

Question 126656This question is from textbook Beginning Algebra
: 8x-4y=16
y=2x-4
Solve by substition
4y=8x-16
divide both sides by 4y
y=8x-16/4
y=8x/4+16/4
y=4x/2+16/4
reduce
y=2x+4
Upon plugging top equation of y into bottom equation, I became confused I came up with
y=2x-4 and y=2x+4
I must have done something wrong along the line

This question is from textbook Beginning Algebra

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Start with the given system
8x-4y=16
y=2x-4



8x-4%282x-4%29=16 Plug in y=2x-4 into the first equation. In other words, replace each y with 2x-4. Notice we've eliminated the y variables. So we now have a simple equation with one unknown.


8x-8x%2B16=16 Distribute


16=16 Combine like terms on the left side


0=16-16Subtract 16 from both sides


0=0 Combine like terms on the right side



Since this equation is always true for any x value, this means x can equal any number. So there are an infinite number of solutions.