SOLUTION: Solve the system by the method of your choice: x=9y-9 -2x+18y=18 If you could please answer this by December 14th that would be awesome!! Also could you give me step by step

Algebra ->  Graphs -> SOLUTION: Solve the system by the method of your choice: x=9y-9 -2x+18y=18 If you could please answer this by December 14th that would be awesome!! Also could you give me step by step       Log On


   

Question 384317: Solve the system by the method of your choice:
x=9y-9
-2x+18y=18
If you could please answer this by December 14th that would be awesome!!
Also could you give me step by step instructions on how to solve problems like this. Thank You so much. Erin
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
-2x%2B18y=18 Start with the second equation.


-2%289y-9%29%2B18y=18 Plug in x=9y-9. Basically, replace EVERY 'x' with '9y-9'


-18y%2B18%2B18y=18 Distribute.


0y%2B18=18 Combine like terms on the left side.


0y=18-18 Subtract 18 from both sides.


0y=0 Combine like terms on the right side.


0=0 Simplify.


Since this equation is ALWAYS true for any y value, this means y can equal any number.


So there are an infinite number of solutions.


This then translates to the fact that the system of equations has an infinite number of solutions.


So the system is both consistent and dependent.