SOLUTION: x+7y=4 (1) x=8-7y (2) What is the solution of the system?

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: x+7y=4 (1) x=8-7y (2) What is the solution of the system?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 146773: x+7y=4 (1)
x=8-7y (2)
What is the solution of the system?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Start with the given system
x%2B7y=4
x=8-7y



8-7y%2B7y=4 Plug in x=8-7y into the first equation. In other words, replace each x with 8-7y. Notice we've eliminated the x variables. So we now have a simple equation with one unknown.


8=4 Combine like terms on the left side


0=4-8Subtract 8 from both sides


0=-4 Combine like terms on the right side


Since this equation is never true for any y value, this means there are no solutions.


Notice if we graph the two equations, we can see that the two lines are parallel and will never intersect. So this verifies our answer.


+graph%28+500%2C+500%2C+-5%2C+5%2C+-5%2C+5%2C+%284-x%29%2F%287%29%2C+%288-x%29%2F%287%29%29+ Graph of x%2B7y=4 (red) and x=8-7y (green)