SOLUTION: I have tried this but I am having trouble, can you please help. Use substitution to solve each system. If it does not have one solution then put no solution or indinitely many so

Algebra ->  Expressions-with-variables -> SOLUTION: I have tried this but I am having trouble, can you please help. Use substitution to solve each system. If it does not have one solution then put no solution or indinitely many so      Log On


   

Question 181877: I have tried this but I am having trouble, can you please help. Use substitution to solve each system. If it does not have one solution then put no solution or indinitely many solutions. 4X-5Y=-7 Y=5X
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

Start with the given system
4x-5y=-7
y=5x





4x-5%285x%29=-7 Plug in y=5x into the first equation. In other words, replace each y with 5x. Notice we've eliminated the y variables. So we now have a simple equation with one unknown.


4x-25x=-7 Distribute


-21x=-7 Combine like terms on the left side


x=%28-7%29%2F%28-21%29 Divide both sides by -21 to isolate x



x=1%2F3 Reduce




Now that we know that x=1%2F3, we can plug this into y=5x to find y



y=5%281%2F3%29 Substitute 1%2F3 for each x


y=5%2F3 Multiply


So our answer is x=1%2F3 and y=5%2F3 which also looks like